jshell 01.10.2020

Last login: Thu Oct  1 14:34:39 on ttys000
MacBook-Pro-di-Leonardo:~ leonardo$ jshell
|  Welcome to JShell -- Version 13.0.2
|  For an introduction type: /help intro

jshell> public interface IntMultiSet  {
   ...> /**
   ...> * Restitusice il numero delle occorrence dell’intero elem nel multi-insieme. * Apublic interface IntMultiSet  {nsieme restituisce 0
   ...> /**
   ...> * Restitusice il numero delle occorrence dell’intero elem nel multi-insi
eme. * A elem non appartimene al multiinsieme restituisce 0
   ...> **/ggiunge al multi-insieme una occorrenza di elem
   ...>              int getCount(int elem);
   ...> /**          void add(int elem);
   ...> * Aggiunge al multi-insieme una occorrenza di elem
   ...>              * */e di elem al multi-insieme **/
   ...>              void add(int elem); int n);
   ...> /**
   ...> * Aggiunge n copie di elem al multi-insieme **/-insieme. * Restituisce false se              void  add(int elem, int n);
   ...> /**
   ...> * Rimuove tutte le occorrenze di elem dal multi-insieme. * Restituisce f
alse se elem non e’ presente
   ...> */Rimuove n copie of di elem dal multi-insieme * Restituisce false se elem non e             boolean remove(int elem);
   ...> /**          * */
   ...> * Rimuove n copie of di elem dal multi-insieme * Restituisce false se el
em non e’ presente
   ...>              * */mero degli elementi del multi-insieme. **/
   ...>              boolean remove(int elem, int n);
   ...> /**
        * Restuisce il numero degli elementi del multi-insieme. **/
        int size(); }

|  created interface IntMultiSet

jshell>

jshell>

jshell> public class Foo {
   ...> private int a[];
   ...>   class Foo (int[] arr_in) {
   ...>     a = arr_in;
   ...>   }
   ...>
   ...> }
|  Error:
|  '{' expected
|    class Foo (int[] arr_in) {
|             ^
|  Error:
|  ';' expected
|    class Foo (int[] arr_in) {
|                           ^
|  Error:
|  reached end of file while parsing
|  }
|   ^

jshell> public class Foo {
   ...> private int a[];
   ...>   class Foo(int[] arr_in) {
   ...>     a = arr_in;
   ...>   }
   ...>
   ...> }
|  Error:
|  '{' expected
|    class Foo(int[] arr_in) {
|             ^
|  Error:
|  ';' expected
|    class Foo(int[] arr_in) {
|                          ^
|  Error:
|  reached end of file while parsing
|  }
|   ^

jshell> public class Foo {
   ...> private int a[];
   ...>   class Foo(int arr_in[]) {
   ...>     a = arr_in;
   ...>   }
   ...>
   ...> }
|  Error:
|  '{' expected
|    class Foo(int arr_in[]) {
|             ^
|  Error:
|  ';' expected
|    class Foo(int arr_in[]) {
|                          ^
|  Error:
|  reached end of file while parsing
|  }
|   ^

jshell>

jshell>

jshell>

jshell>

jshell> public class Foo {
   ...> private int a[];
   ...>   public Foo(int arr_in[]) {
   ...>     a = arr_in;
   ...>   }
   ...>
   ...> }
|  created class Foo

jshell> private int[] a;
a ==> null

jshell> private int[] a = new int[5];
a ==> int[5] { 0, 0, 0, 0, 0 }

jshell> System.out.println("a length" + a.length);
a length5

jshell> int a[] = new int[5];
a ==> int[5] { 0, 0, 0, 0, 0 }

jshell> a[1] = 3;
$7 ==> 3

jshell> a[2] = 5;
$8 ==> 5

jshell> a[3] = 7;
$9 ==> 7

jshell> a[4] = 9;
$10 ==> 9

jshell> a[5] = 9
|  Exception java.lang.ArrayIndexOutOfBoundsException: Index 5 out of bounds for length 5
|        at (#11:1)

jshell> a[0] = 1;
$12 ==> 1

jshell> int[] b = new int[5];
b ==> int[5] { 0, 0, 0, 0, 0 }

jshell> b[0]= 281;
$14 ==> 281

jshell> b[1] = 293
$15 ==> 293

jshell> b[2] = 1;
$16 ==> 1

jshell> b[3]  = 203
$17 ==> 203

jshell> b[4] = 92392;
$18 ==> 92392

jshell> public int getCount(int elem) {
   ...>     //cerca l'elemento
   ...>     for(int i = 0; i < a.lenght; i++)
   ...>       if(a[i] == elem)
   ...>         return b[i];
   ...>     return 0;
   ...>   }
|  Error:
|  cannot find symbol
|    symbol:   variable lenght
|      for(int i = 0; i < a.lenght; i++)
|                         ^------^

jshell> public int[] a = a;
a ==> int[5] { 1, 3, 5, 7, 9 }

jshell> public int getCount(int elem) {
   ...>     //cerca l'elemento
   ...>     for(int i = 0; i < a.lenght; i++)
   ...>       if(a[i] == elem)
   ...>         return b[i];
   ...>     return 0;
   ...>   }
|  Error:
|  cannot find symbol
|    symbol:   variable lenght
|      for(int i = 0; i < a.lenght; i++)
|                         ^------^

jshell> public class Foo implements IntMultiSet {
   ...>   private int[] a;
   ...>   private int[] b;
   ...>   public Foo(int a_in[], int b_in) {
   ...>     a = a_in;
   ...>     b = b_in;
   ...>   }
   ...>
   ...>   public int getCount(int elem) {
   ...>     //cerca l'elemento
   ...>     for(int i = 0; i < a.lenght; i++)
   ...>       if(a[i] == elem)
   ...>         return b[i];
   ...>     return 0;
   ...>   }
   ...> }
   ...>
|  Error:
|  Foo is not abstract and does not override abstract method size() in IntMultiSet
|  public class Foo implements IntMultiSet {
|  ^----------------------------------------...
|  Error:
|  incompatible types: int cannot be converted to int[]
|      b = b_in;
|          ^--^
|  Error:
|  cannot find symbol
|    symbol:   variable lenght
|      for(int i = 0; i < a.lenght; i++)
|                         ^------^

jshell> public class Foo  {
   ...>   private int[] a;
   ...>   private int[] b;
   ...>   public Foo(int a_in[], int b_in) {
   ...>     a = a_in;
   ...>     b = b_in;
   ...>   }
   ...>
   ...>   public int getCount(int elem) {
   ...>     //cerca l'elemento
   ...>     for(int i = 0; i < a.lenght; i++)
   ...>       if(a[i] == elem)
   ...>         return b[i];
   ...>     return 0;
   ...>   }
   ...> }
|  Error:
|  incompatible types: int cannot be converted to int[]
|      b = b_in;
|          ^--^
|  Error:
|  cannot find symbol
|    symbol:   variable lenght
|      for(int i = 0; i < a.lenght; i++)
|                         ^------^

jshell> public class Foo {
   ...>   private int[] a;
   ...>   private int[] b;
   ...>   public Foo(int a_in[], int b_in[]) {
   ...>     a = a_in;
   ...>     b = b_in;
   ...>   }
   ...>
   ...>   public int getCount(int elem) {
   ...>     //cerca l'elemento
   ...>     for(int i = 0; i < a.lenght; i++)
   ...>       if(a[i] == elem)
   ...>         return b[i];
   ...>     return 0;
   ...>   }
   ...> }
   ...>
|  Error:
|  cannot find symbol
|    symbol:   variable lenght
|      for(int i = 0; i < a.lenght; i++)
|                         ^------^

jshell> public class Foo {
   ...>   int[] a;
   ...>   private int[] b;
   ...>   public Foo(int a_in[], int b_in[]) {
   ...>     a = a_in;
   ...>     b = b_in;
   ...>   }
   ...>
   ...>   public int getCount(int elem) {
   ...>     //cerca l'elemento
   ...>     for(int i = 0; i < a.lenght; i++)
   ...>       if(a[i] == elem)
   ...>         return b[i];
   ...>     return 0;
   ...>   }
   ...> }
   ...>
|  Error:
|  cannot find symbol
|    symbol:   variable lenght
|      for(int i = 0; i < a.lenght; i++)
|                         ^------^

jshell> public class Foo {
   ...>   public int[] a;
   ...>   private int[] b;
   ...>   public Foo(int a_in[], int b_in[]) {
   ...>     a = a_in;
   ...>     b = b_in;
   ...>   }
   ...>
   ...>   public int getCount(int elem) {
   ...>     //cerca l'elemento
   ...>     for(int i = 0; i < a.lenght; i++)
   ...>       if(a[i] == elem)
   ...>         return b[i];
   ...>     return 0;
   ...>   }
   ...> }
   ...>
|  Error:
|  cannot find symbol
|    symbol:   variable lenght
|      for(int i = 0; i < a.lenght; i++)
|                         ^------^

jshell> public class Foo {
   ...>   private int[] a;
   ...>   private int[] b;
   ...>   public Foo(int a_in[], int b_in[]) {
   ...>     a = a_in;
   ...>     b = b_in;
   ...>   }
   ...>
   ...>   public int getCount(int elem) {
   ...>     //cerca l'elemento
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)
   ...>         return b[i];
   ...>     return 0;
   ...>   }
   ...> }
   ...>
|  created class Foo

jshell> a;
a ==> int[5] { 1, 3, 5, 7, 9 }

jshell> b;
b ==> int[5] { 281, 293, 1, 203, 92392 }

jshell> getCount(7);
|  Error:
|  cannot find symbol
|    symbol:   method getCount(int)
|  getCount(7);
|  ^------^

jshell> public int getCount(int elem) {
   ...>     //cerca l'elemento
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)
   ...>         return b[i];
   ...>     return 0;
   ...>   }
|  created method getCount(int)

jshell> getCount(7);
$24 ==> 203

jshell> public void add(int elem, int n) {
   ...>     //aggiunge n occorrenze di elem
   ...>     private int position = position(elem);
   ...>     if(position == -1) {
   ...>       //l'elemento non è presente nel multi-insieme, va aggiunta una posizione all'array
   ...>       a = java.util.Arrays.copyOf(a, a.length + 1);
   ...>       b = java.util.Arrays.copyOf(b, b.length + 1);
   ...>       position = a.length - 1;
   ...>       a[position] = elem;
   ...>       b[position] = 0;
   ...>
   ...>     }
   ...>
   ...>     b[position]+=n;
   ...>   }
|  Error:
|  illegal start of expression
|      private int position = position(elem);
|      ^

jshell> public void add(int elem, int n) {
   ...>     //aggiunge n occorrenze di elem
   ...>     int position = position(elem);
   ...>     if(position == -1) {
   ...>       //l'elemento non è presente nel multi-insieme, va aggiunta una posizione all'array
   ...>       a = java.util.Arrays.copyOf(a, a.length + 1);
   ...>       b = java.util.Arrays.copyOf(b, b.length + 1);
   ...>       position = a.length - 1;
   ...>       a[position] = elem;
   ...>       b[position] = 0;
   ...>
   ...>     }
   ...>
   ...>     b[position]+=n;
   ...>   }
|  created method add(int,int), however, it cannot be invoked until method position(int) is declared

jshell> public void position(int elem) {
   ...>     //cerca la posizione dell'elemento elem in a. Se lo trova restituisce la posizione altrimenti -1
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)
   ...>         return i;
   ...>     return -1;
   ...>   }
|  Error:
|  incompatible types: unexpected return value
|          return i;
|                 ^
|  Error:
|  incompatible types: unexpected return value
|      return -1;
|             ^^

jshell> public int position(int elem) {
   ...>     //cerca la posizione dell'elemento elem in a. Se lo trova restituisce la posizione altrimenti -1
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)
   ...>         return i;
   ...>     return -1;
   ...>   }
|  created method position(int)

jshell> public void add(int elem, int n) {
   ...>     //aggiunge n occorrenze di elem
   ...>     int position = position(elem);
   ...>     if(position == -1) {
   ...>       //l'elemento non è presente nel multi-insieme, va aggiunta una posizione all'array
   ...>       a = java.util.Arrays.copyOf(a, a.length + 1);
   ...>       b = java.util.Arrays.copyOf(b, b.length + 1);
   ...>       position = a.length - 1;
   ...>       a[position] = elem;
   ...>       b[position] = 0;
   ...>
   ...>     }
   ...>
   ...>     b[position]+=n;
   ...>   }
|  modified method add(int,int)

jshell> a;
a ==> int[5] { 1, 3, 5, 7, 9 }

jshell> b;
b ==> int[5] { 281, 293, 1, 203, 92392 }

jshell> add(1, 3);

jshell> a;
a ==> int[5] { 1, 3, 5, 7, 9 }

jshell> b;
b ==> int[5] { 284, 293, 1, 203, 92392 }

jshell> add(8, 1023910);

jshell> a;
a ==> int[6] { 1, 3, 5, 7, 9, 8 }

jshell> b;
b ==> int[6] { 284, 293, 1, 203, 92392, 1023910 }

jshell> a;
a ==> int[6] { 1, 3, 5, 7, 9, 8 }

jshell> a = java.util.Arrays.copyOf(a, a.length - 1);
a ==> int[5] { 1, 3, 5, 7, 9 }

jshell> public boolean remove(int elem, int n) {
   ...>     int position = position(elem);
   ...>     if(position == -1)
   ...>       return false;
   ...>
   ...>     b[position]-=n;
   ...>     if(b[position] <= 0) {
   ...>       //l'elemento va eliminato dall'array a e b
   ...>       for(int i = position + 1; i < a.length; i++) {
   ...>         a[i - 1] = a[i];
   ...>         b[i - 1] = b[i];
   ...>       }
   ...>       a = java.util.Arrays.copyOf(a, a.length - 1);
   ...>       b = java.util.Arrays.copyOf(b, b.length - 1);
   ...>     }
   ...>
   ...>     return true;
   ...>   }
|  created method remove(int,int)

jshell> a;
a ==> int[5] { 1, 3, 5, 7, 9 }

jshell> remve(2932, 1);
|  Error:
|  cannot find symbol
|    symbol:   method remve(int,int)
|  remve(2932, 1);
|  ^---^

jshell> remove(2932, 1);
$40 ==> false

jshell> a; b;
a ==> int[5] { 1, 3, 5, 7, 9 }
b ==> int[6] { 284, 293, 1, 203, 92392, 1023910 }

jshell> remove(1, 280);
$43 ==> true

jshell> a;b;
a ==> int[5] { 1, 3, 5, 7, 9 }
b ==> int[6] { 4, 293, 1, 203, 92392, 1023910 }

jshell> remove(3, 1);
$46 ==> true

jshell> a;b;
a ==> int[5] { 1, 3, 5, 7, 9 }
b ==> int[6] { 4, 292, 1, 203, 92392, 1023910 }

jshell> b = java.util.Arrays.copyOf(b, b.length - 1);
b ==> int[5] { 4, 292, 1, 203, 92392 }

jshell> a;b;
a ==> int[5] { 1, 3, 5, 7, 9 }
b ==> int[5] { 4, 292, 1, 203, 92392 }

jshell> remove(1, 4);
$52 ==> true

jshell> a;b;
a ==> int[4] { 3, 5, 7, 9 }
b ==> int[4] { 292, 1, 203, 92392 }

jshell> remove(5, 3);
$55 ==> true

jshell> a;b;
a ==> int[3] { 3, 7, 9 }
b ==> int[3] { 292, 203, 92392 }

jshell> remove(9, 9232983);
$58 ==> true

jshell> a;b;
a ==> int[2] { 3, 7 }
b ==> int[2] { 292, 203 }

jshell> public int size() {
   ...>     int sum = 0;
   ...>     for(int i = 0; i < b.length; i++)
   ...>       sum+=b[i];
   ...>     return sum;
   ...>   }
|  created method size()

jshell> size();
$62 ==> 495

jshell> public class Foo implements IntMultiSet{
   ...>   private int[] a;
   ...>   private int[] b;
   ...>   public Foo(int a_in[], int b_in[]) {
   ...>     a = a_in;
   ...>     b = b_in;
   ...>   }
   ...>
   ...>   public int getCount(int elem) {
   ...>     //cerca l'elemento e ne restituisce quante copie ve ne sono
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)
   ...>         return b[i];
   ...>     return 0;
   ...>   }
   ...>
   ...>   public int position(int elem) {
   ...>     //cerca la posizione dell'elemento elem in a. Se lo trova restituisce la posizione altrimenti -1
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)
   ...>         return i;
   ...>     return -1;
   ...>   }
   ...>
   ...>   public void add(int elem, int n) {
   ...>     //aggiunge n occorrenze di elem
   ...>     int position = position(elem);
   ...>     if(position == -1) {
   ...>       //l'elemento non è presente nel multi-insieme, va aggiunta una posizione all'array
   ...>       a = java.util.Arrays.copyOf(a, a.length + 1);
   ...>       b = java.util.Arrays.copyOf(b, b.length + 1);
   ...>       position = a.length - 1;
   ...>       a[position] = elem;
   ...>       b[position] = 0;
   ...>     }
   ...>
   ...>     b[position]+=n;
   ...>   }
   ...>
   ...>   public void add(int elem) {
   ...>     //aggiunge una copia di elem nell'array
   ...>     add(elem, 1);
   ...>   }
   ...>
   ...>   public boolean remove(int elem, int n) {
   ...>     int position = position(elem);
   ...>     if(position == -1)
   ...>       return false;
   ...> public class Foo implements IntMultiSet{
   ...>   private int[] a;;
   ...>   private int[] b; <= 0) {
   ...>   public Foo(int a_in[], int b_in[]) {rray a e b
   ...>     a = a_in; i = position + 1; i < a.length; i++) {
   ...>     b = b_in; 1] = a[i];
   ...>   }     b[i - 1] = b[i];
   ...>       }
   ...>   public int getCount(int elem) {(a, a.length - 1);
   ...>     //cerca l'elemento e ne restituisce quante copie ve ne sono
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)
   ...>         return b[i];
   ...>     return 0;
   ...>   }
   ...>   public int size() {
   ...>   public int position(int elem) {
   ...>     //cerca la posizione dell'elemento elem in a. Se lo trova restituisc
e la posizione altrimenti -1
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)
   ...>         return i;
   ...>     return -1;
   ...>   }

          public void add(int elem, int n) {
            //aggiunge n occorrenze di elem
            int position = position(elem);
            if(position == -1) {
              //l'elemento non è presente nel multi-insieme, va aggiunta una pos
izione all'array
              a = java.util.Arrays.copyOf(a, a.length + 1);
              b = java.util.Arrays.copyOf(b, b.length + 1);
              position = a.length - 1;
              a[position] = elem;
              b[position] = 0;
            }

            b[position]+=n;
          }

          public void add(int elem) {
            //aggiunge una copia di elem nell'array
            add(elem, 1);
          }

          public boolean remove(int elem, int n) {
            int position = position(elem);
            if(position == -1)
              return false;

            b[position]-=n;
            if(b[position] <= 0) {
              //l'elemento va eliminato dall'array a e b
              for(int i = position + 1; i < a.length; i++) {
                a[i - 1] = a[i];
                b[i - 1] = b[i];
              }
              a = java.util.Arrays.copyOf(a, a.length - 1);
              b = java.util.Arrays.copyOf(b, b.length - 1);
            }

            return true;
          }

          public int size() {
            int sum = 0;
            for(int i = 0; i < b.length; i++)
              sum+=b[i];
            return sum;
          }

        }

|  Error:
|  Foo is not abstract and does not override abstract method remove(int) in IntMultiSet
|  public class Foo implements IntMultiSet{
|  ^---------------------------------------...

jshell> public class Foo implements IntMultiSet{
   ...>   private int[] a;
   ...>   private int[] b;
   ...>   public Foo(int a_in[], int b_in[]) {
   ...>     a = a_in;
   ...>     b = b_in;
   ...>   }
   ...>
   ...>   public int getCount(int elem) {
   ...>     //cerca l'elemento e ne restituisce quante copie ve ne sono
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)
   ...>         return b[i];
   ...>     return 0;
   ...>   }
   ...>
   ...>   public int position(int elem) {
   ...>     //cerca la posizione dell'elemento elem in a. Se lo trova restituisce la posizione altrimenti -1
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)
   ...>         return i;
   ...>     return -1;
   ...>   }
   ...>
   ...>   public void add(int elem, int n) {
   ...>     //aggiunge n occorrenze di elem
   ...>     int position = position(elem);
   ...>     if(position == -1) {
   ...>       //l'elemento non è presente nel multi-insieme, va aggiunta una posizione all'array
   ...>       a = java.util.Arrays.copyOf(a, a.length + 1);
   ...>       b = java.util.Arrays.copyOf(b, b.length + 1);
   ...>       position = a.length - 1;
   ...>       a[position] = elem;
   ...>       b[position] = 0;
   ...>     }
   ...>
   ...>     b[position]+=n;
   ...>   }
   ...>
   ...>   public void add(int elem) {
   ...>     //aggiunge una copia di elem nell'array
   ...>     add(elem, 1);
   ...>   }
   ...>
   ...>   public boolean remove(int elem, int n) {
   ...>     int position = position(elem);
   ...>     if(position == -1)
   ...>       return false;
   ...>
   ...>     b[position]-=n;
   ...>     if(b[position] <= 0) {
   ...>       //l'elemento va eliminato dall'array a e b
   ...> public class Foo implements IntMultiSet{ngth; i++) {
   ...>   private int[] a; a[i];
   ...>   private int[] b; b[i];
   ...>   public Foo(int a_in[], int b_in[]) {
   ...>     a = a_in;a.util.Arrays.copyOf(a, a.length - 1);
   ...>     b = b_in;a.util.Arrays.copyOf(b, b.length - 1);
   ...>   } }
   ...>
   ...>   public int getCount(int elem) {
   ...>     //cerca l'elemento e ne restituisce quante copie ve ne sono
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)e(int elem) {
   ...>         return b[i];em, 1);
   ...>     return 0;
   ...>   }
   ...>   public int size() {
   ...>   public int position(int elem) {
   ...>     //cerca la posizione dell'elemento elem in a. Se lo trova restituisc
e la posizione altrimenti -1
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)
   ...>         return i;
   ...>     return -1;
   ...>   }

          public void add(int elem, int n) {
            //aggiunge n occorrenze di elem
            int position = position(elem);
            if(position == -1) {
              //l'elemento non è presente nel multi-insieme, va aggiunta una pos
izione all'array
              a = java.util.Arrays.copyOf(a, a.length + 1);
              b = java.util.Arrays.copyOf(b, b.length + 1);
              position = a.length - 1;
              a[position] = elem;
              b[position] = 0;
            }

            b[position]+=n;
          }

          public void add(int elem) {
            //aggiunge una copia di elem nell'array
            add(elem, 1);
          }

          public boolean remove(int elem, int n) {
            int position = position(elem);
            if(position == -1)
              return false;

            b[position]-=n;
            if(b[position] <= 0) {
              //l'elemento va eliminato dall'array a e b
              for(int i = position + 1; i < a.length; i++) {
                a[i - 1] = a[i];
                b[i - 1] = b[i];
              }
              a = java.util.Arrays.copyOf(a, a.length - 1);
              b = java.util.Arrays.copyOf(b, b.length - 1);
            }

            return true;
          }

          public boolean remove(int elem) {
            return remove(elem, 1);
          }

          public int size() {
            int sum = 0;
            for(int i = 0; i < b.length; i++)
              sum+=b[i];
            return sum;
          }

        }

|  created class Foo

jshell> a;
a ==> int[2] { 3, 7 }

jshell> int a[5] = { 1, 3, 5, 7, 9 }
|  Error:
|  ']' expected
|  int a[5] = { 1, 3, 5, 7, 9 };
|        ^

jshell> add (19, 382);

jshell> add(283, 4924);

jshell> add (1283, 293020392);

jshell> a;b;
a ==> int[5] { 3, 7, 19, 283, 1283 }
b ==> int[5] { 292, 203, 382, 4924, 293020392 }

jshell> Foo obj = new obj(a, b);
|  Error:
|  cannot find symbol
|    symbol:   class obj
|  Foo obj = new obj(a, b);
|                ^-^

jshell> Foo obj = new Foo(a, b);
obj ==> Foo@200a570f

jshell> obj.size;
|  Error:
|  cannot find symbol
|    symbol:   variable size
|  obj.size;
|  ^------^

jshell> obj.size();
$71 ==> 293026193

jshell> a;b;
a ==> int[5] { 3, 7, 19, 283, 1283 }
b ==> int[5] { 292, 203, 382, 4924, 293020392 }

jshell> remove(3, 2934392);
$74 ==> true

jshell> int[] arr_fin = new int[0];
arr_fin ==> int[0] {  }

jshell> obj.arr1;
|  Error:
|  cannot find symbol
|    symbol:   variable arr1
|  obj.arr1;
|  ^------^

jshell> obj.a;
|  Error:
|  a has private access in Foo
|  obj.a;
|  ^---^

jshell> public class Foo implements IntMultiSet{
   ...>   public int[] a;
   ...>   public int[] b;
   ...>   public Foo(int a_in[], int b_in[]) {
   ...>     a = a_in;
   ...>     b = b_in;
   ...>   }
   ...>
   ...>   public int getCount(int elem) {
   ...>     //cerca l'elemento e ne restituisce quante copie ve ne sono
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)
   ...>         return b[i];
   ...>     return 0;
   ...>   }
   ...>
   ...>   public int position(int elem) {
   ...>     //cerca la posizione dell'elemento elem in a. Se lo trova restituisce la posizione altrimenti -1
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)
   ...>         return i;
   ...>     return -1;
   ...>   }
   ...>
   ...>   public void add(int elem, int n) {
   ...>     //aggiunge n occorrenze di elem
   ...>     int position = position(elem);
   ...>     if(position == -1) {
   ...>       //l'elemento non è presente nel multi-insieme, va aggiunta una posizione all'array
   ...>       a = java.util.Arrays.copyOf(a, a.length + 1);
   ...>       b = java.util.Arrays.copyOf(b, b.length + 1);
   ...>       position = a.length - 1;
   ...>       a[position] = elem;
   ...>       b[position] = 0;
   ...>     }
   ...>
   ...>     b[position]+=n;
   ...>   }
   ...>
   ...>   public void add(int elem) {
   ...>     //aggiunge una copia di elem nell'array
   ...>     add(elem, 1);
   ...>   }
   ...>
   ...>   public boolean remove(int elem, int n) {
   ...>     int position = position(elem);
   ...>     if(position == -1)
   ...>       return false;
   ...>
   ...>     b[position]-=n;
   ...>     if(b[position] <= 0) {
   ...> public class Foo implements IntMultiSet{ay a e b
   ...>   public int[] a; position + 1; i < a.length; i++) {
   ...>   public int[] b;= a[i];
   ...>   public Foo(int a_in[], int b_in[]) {
   ...>     a = a_in;
   ...>     b = b_in;a.util.Arrays.copyOf(a, a.length - 1);
   ...>   }   b = java.util.Arrays.copyOf(b, b.length - 1);
   ...>     }
   ...>   public int getCount(int elem) {
   ...>     //cerca l'elemento e ne restituisce quante copie ve ne sono
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)
   ...>         return b[i];ove(int elem) {
   ...>     return 0;move(elem, 1);
   ...>   }
   ...>
   ...>   public int position(int elem) {
   ...>     //cerca la posizione dell'elemento elem in a. Se lo trova restituisc
e la posizione altrimenti -1 < b.length; i++)
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)
   ...>         return i;
   ...>     return -1;
   ...>   }

          public void add(int elem, int n) {
            //aggiunge n occorrenze di elem
            int position = position(elem);
            if(position == -1) {
              //l'elemento non è presente nel multi-insieme, va aggiunta una pos
izione all'array
              a = java.util.Arrays.copyOf(a, a.length + 1);
              b = java.util.Arrays.copyOf(b, b.length + 1);
              position = a.length - 1;
              a[position] = elem;
              b[position] = 0;
            }

            b[position]+=n;
          }

          public void add(int elem) {
            //aggiunge una copia di elem nell'array
            add(elem, 1);
          }

          public boolean remove(int elem, int n) {
            int position = position(elem);
            if(position == -1)
              return false;

            b[position]-=n;
            if(b[position] <= 0) {
              //l'elemento va eliminato dall'array a e b
              for(int i = position + 1; i < a.length; i++) {
                a[i - 1] = a[i];
                b[i - 1] = b[i];
              }
              a = java.util.Arrays.copyOf(a, a.length - 1);
              b = java.util.Arrays.copyOf(b, b.length - 1);
            }

            return true;
          }

          public boolean remove(int elem) {
            return remove(elem, 1);
          }

          public int size() {
            int sum = 0;
            for(int i = 0; i < b.length; i++)
              sum+=b[i];
            return sum;
          }
        }

|  replaced class Foo
|    update replaced variable obj, reset to null

jshell> public class Foo implements IntMultiSet{
   ...>   public int[] a;
   ...>   public int[] b;
   ...>   public Foo(int a_in[], int b_in[]) {
   ...>     a = a_in;
   ...>     b = b_in;
   ...>   }
   ...>
   ...>   public int getCount(int elem) {
   ...>     //cerca l'elemento e ne restituisce quante copie ve ne sono
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)
   ...>         return b[i];
   ...>     return 0;
   ...>   }
   ...>
   ...>   public int position(int elem) {
   ...>     //cerca la posizione dell'elemento elem in a. Se lo trova restituisce la posizione altrimenti -1
   ...>     for(int i = 0; i < a.length; i++)
   ...>       if(a[i] == elem)
   ...>         return i;
   ...>     return -1;
   ...>   }
   ...>
   ...>   public void add(int elem, int n) {
   ...>     //aggiunge n occorrenze di elem
   ...>     int position = position(elem);
   ...>     if(position == -1) {
   ...>       //l'elemento non è presente nel multi-insieme, va aggiunta una posizione all'array
   ...>       a = java.util.Arrays.copyOf(a, a.length + 1);
   ...>       b = java.util.Arrays.copyOf(b, b.length + 1);
   ...>       position = a.length - 1;
   ...>       a[position] = elem;
   ...>       b[position] = 0;
   ...>     }
   ...>
   ...>     b[position]+=n;
   ...>   }
   ...>
   ...>   public void add(int elem) {
   ...>     //aggiunge una copia di elem nell'array
   ...>     add(elem, 1);
   ...>   }
   ...>
   ...>   public boolean remove(int elem, int n) {
   ...>     int position = position(elem);
   ...>     if(position == -1)
   ...>       return false;
   ...>
   ...>     b[position]-=n;
   ...>



















































        obj.a;
|  Exception java.lang.NullPointerException
|        at (#77:1)

jshell> obj.a;
|  Exception java.lang.NullPointerException
|        at (#78:1)

jshell> obj;
obj ==> null

jshell> Foo obj = new Foo(a, b);
obj ==> Foo@299a06ac

jshell> obj;
obj ==> Foo@299a06ac

jshell> obj.a;
$82 ==> int[4] { 7, 19, 283, 1283 }

jshell> obj1.a.length
|  Error:
|  package obj1 does not exist
|  obj1.a.length
|  ^----^

jshell> obj.a.length;
$83 ==> 4

jshell> public void Union(Foo obj1, Foo obj2) {
   ...>   private int[] arr_a_tmp = new int[0];
   ...>   private int arr_b_tmp = new int[0];
   ...>   Foo obj_fin = new Foo(arr_a_tmp, arr_b_tmp);
   ...>   for(int i = 0; i < obj1.a.length; i++) {
   ...>     if(obj2.position(obj1.a[i]) != -1)
   ...>       obj_fin.add(obj1.a[i], max(obj1.b[i], obj2.position(obj1.a[i])));
   ...>   }
   ...> }
|  Error:
|  illegal start of expression
|    private int[] arr_a_tmp = new int[0];
|    ^

jshell> public void Union(Foo obj1, Foo obj2) {
   ...>   int[] arr_a_tmp = new int[0];
   ...>   int arr_b_tmp = new int[0];
   ...>   Foo obj_fin = new Foo(arr_a_tmp, arr_b_tmp);
   ...>   for(int i = 0; i < obj1.a.length; i++) {
   ...>     if(obj2.position(obj1.a[i]) != -1)
   ...>       obj_fin.add(obj1.a[i], max(obj1.b[i], obj2.position(obj1.a[i])));
   ...>   }
   ...> }
|  Error:
|  incompatible types: int[] cannot be converted to int
|    int arr_b_tmp = new int[0];
|                    ^--------^
|  Error:
|  incompatible types: int cannot be converted to int[]
|    Foo obj_fin = new Foo(arr_a_tmp, arr_b_tmp);
|                                     ^-------^
|  Error:
|  cannot find symbol
|    symbol:   method max(int,int)
|        obj_fin.add(obj1.a[i], max(obj1.b[i], obj2.position(obj1.a[i])));
|                               ^-^

jshell> public int max (int el1, int el2) {
   ...>   if(el1 > el2)
   ...>     return el1;
   ...>   else
   ...>     return el2;
   ...> }
|  created method max(int,int)

jshell> public void Union(Foo obj1, Foo obj2) {
   ...>   int[] arr_a_tmp = new int[0];
   ...>   int arr_b_tmp = new int[0];
   ...>   Foo obj_fin = new Foo(arr_a_tmp, arr_b_tmp);
   ...>   for(int i = 0; i < obj1.a.length; i++) {
   ...>     if(obj2.position(obj1.a[i]) != -1)
   ...>       obj_fin.add(obj1.a[i], max(obj1.b[i], obj2.position(obj1.a[i])));
   ...>   }
   ...> }
   ...>
|  Error:
|  incompatible types: int[] cannot be converted to int
|    int arr_b_tmp = new int[0];
|                    ^--------^
|  Error:
|  incompatible types: int cannot be converted to int[]
|    Foo obj_fin = new Foo(arr_a_tmp, arr_b_tmp);
|                                     ^-------^

jshell> public void Union(Foo obj1, Foo obj2) {
   ...>   int[] arr_a_tmp = new int[0];
   ...>   int arr_b_tmp = new int[0];
   ...>   Foo obj_fin = new Foo(arr_a_tmp, arr_b_tmp);
   ...>   for(int i = 0; i < obj1.a.length; i++) {
   ...>     if(obj2.position(obj1.a[i]) != -1)
   ...>       obj_fin.add(obj1.a[i], max(obj1.b[i], obj2.b[obj2.position(obj1.a[i])]);
   ...>   }
   ...> }
|  Error:
|  ')' expected
|        obj_fin.add(obj1.a[i], max(obj1.b[i], obj2.b[obj2.position(obj1.a[i])]);
|                                                                               ^

jshell> public void Union(Foo obj1, Foo obj2) {
   ...>   int[] arr_a_tmp = new int[0];
   ...>   int arr_b_tmp = new int[0];
   ...>   Foo obj_fin = new Foo(arr_a_tmp, arr_b_tmp);
   ...>   for(int i = 0; i < obj1.a.length; i++) {
   ...>     if(obj2.position(obj1.a[i]) != -1)
   ...>       obj_fin.add(obj1.a[i], max(obj1.b[i], obj2.b[obj2.position(obj1.a[i])]));
   ...>   }
   ...> }
|  Error:
|  incompatible types: int[] cannot be converted to int
|    int arr_b_tmp = new int[0];
|                    ^--------^
|  Error:
|  incompatible types: int cannot be converted to int[]
|    Foo obj_fin = new Foo(arr_a_tmp, arr_b_tmp);
|                                     ^-------^

jshell> public void Union(Foo obj1, Foo obj2) {
   ...>   int[] arr_a_tmp = new int[0];
   ...>   int[] arr_b_tmp = new int[0];
   ...>   Foo obj_fin = new Foo(arr_a_tmp, arr_b_tmp);
   ...>   for(int i = 0; i < obj1.a.length; i++) {
   ...>     if(obj2.position(obj1.a[i]) != -1)
   ...>       obj_fin.add(obj1.a[i], max(obj1.b[i], obj2.b[obj2.position(obj1.a[i])]));
   ...>   }
   ...> }
   ...>
|  created method Union(Foo,Foo)

jshell> a;b;
a ==> int[4] { 7, 19, 283, 1283 }
b ==> int[4] { 203, 382, 4924, 293020392 }

jshell> int[] c = new int {7, 19, 28, 39, 27, 47 };
|  Error:
|  '[' expected
|  int[] c = new int {7, 19, 28, 39, 27, 47 };
|                   ^
|  Error:
|  illegal start of expression
|  int[] c = new int {7, 19, 28, 39, 27, 47 };
|                    ^

jshell> int[] c =  {7, 19, 28, 39, 27, 47 };
c ==> int[6] { 7, 19, 28, 39, 27, 47 }

jshell> int[] d = {200, 10, 2391, 28283, 2993, 2939 }
d ==> int[6] { 200, 10, 2391, 28283, 2993, 2939 }

jshell> foo.a;
|  Error:
|  cannot find symbol
|    symbol:   variable foo
|  foo.a;
|  ^-^

jshell> Foo obj1 = new Foo(a, b);
obj1 ==> Foo@5577140b

jshell> Foo obj2 = new Foo(c, d);
obj2 ==> Foo@67f89fa3

jshell> public Foo Union(Foo obj1, Foo obj2) {
   ...>   int[] arr_a_tmp = new int[0];
   ...>   int[] arr_b_tmp = new int[0];
   ...>   Foo obj_fin = new Foo(arr_a_tmp, arr_b_tmp);
   ...>   for(int i = 0; i < obj1.a.length; i++) {
   ...>     if(obj2.position(obj1.a[i]) != -1)
   ...>       obj_fin.add(obj1.a[i], max(obj1.b[i], obj2.b[obj2.position(obj1.a[i])]));
   ...>   }
   ...>   return obj_fin;
   ...> }
|  replaced method Union(Foo,Foo)

jshell> Union(obj1, obj2);
$93 ==> Foo@6073f712

jshell> Foo objunion = Union(obj1, obj2);
objunion ==> Foo@3d04a311

jshell> obj1.a; obj1.b; obj2.a; obj2.b;
$95 ==> int[4] { 7, 19, 283, 1283 }
$96 ==> int[4] { 203, 382, 4924, 293020392 }
$97 ==> int[6] { 7, 19, 28, 39, 27, 47 }
$98 ==> int[6] { 200, 10, 2391, 28283, 2993, 2939 }

jshell> objunion.a; objunion.b;
$99 ==> int[2] { 7, 19 }
$100 ==> int[2] { 203, 382 }

jshell> public int min (int el1, int el2) {
   ...>   if(el1 > el2)
   ...>     return el2;
   ...>   else
   ...>     return el1;
   ...> }
   ...>
   ...> public Foo Intersect(Foo obj1, Foo obj2) {
   ...>   int[] arr_a_tmp = new int[0];
   ...>   int[] arr_b_tmp = new int[0];
   ...>   Foo obj_fin = new Foo(arr_a_tmp, arr_b_tmp);
   ...>   for(int i = 0; i < obj1.a.length; i++) {
   ...>     if(obj2.position(obj1.a[i]) != -1)
   ...>       obj_fin.add(obj1.a[i], min(obj1.b[i], obj2.b[obj2.position(obj1.a[i])]));
   ...>   }
   ...>   return obj_fin;
   ...> }
|  created method min(int,int)
|  created method Intersect(Foo,Foo)

jshell> Foo objintersect = Intersect(obj1,obj2);
objintersect ==> Foo@57fa26b7

jshell> objintersect.a; onjintersect.b;
$104 ==> int[2] { 7, 19 }
|  Error:
|  cannot find symbol
|    symbol:   variable onjintersect
|   onjintersect.b;
|   ^----------^

jshell> objintersect.a; objintersect.b;
$105 ==> int[2] { 7, 19 }
$106 ==> int[2] { 200, 10 }

jshell> public Foo Union(Foo obj1, Foo obj2) {
   ...>   int[] arr_a_tmp = new int[0];
   ...>   int[] arr_b_tmp = new int[0];
   ...>   Foo obj_fin = new Foo(arr_a_tmp, arr_b_tmp);
   ...>   for(int i = 0; i < obj1.a.length; i++)
   ...>     obj_fin.add(obj1.a[i], obj1.b[i]);
   ...>   for(int i = 0; i < obj1.a.length; i++)
   ...>     obj_fin.add(obj2.a[i], obj2.b[i]);
   ...>   return obj_fin;
   ...> }
|  modified method Union(Foo,Foo)

jshell> Foo objunion = Union(obj1, obj2);
objunion ==> Foo@4141d797

jshell> obj1.a; obj1.b; obj2.a; obj2.b; objintersect.a; onjintersect.b; objunion.a; objunion.b;
$109 ==> int[4] { 7, 19, 283, 1283 }
$110 ==> int[4] { 203, 382, 4924, 293020392 }
$111 ==> int[6] { 7, 19, 28, 39, 27, 47 }
$112 ==> int[6] { 200, 10, 2391, 28283, 2993, 2939 }
$113 ==> int[2] { 7, 19 }
|  Error:
|  cannot find symbol
|    symbol:   variable onjintersect
|   onjintersect.b;
|   ^----------^

jshell> obj1.a; obj1.b; obj2.a; obj2.b; objintersect.a; objintersect.b; objunion.a; objunion.b;
$114 ==> int[4] { 7, 19, 283, 1283 }
$115 ==> int[4] { 203, 382, 4924, 293020392 }
$116 ==> int[6] { 7, 19, 28, 39, 27, 47 }
$117 ==> int[6] { 200, 10, 2391, 28283, 2993, 2939 }
$118 ==> int[2] { 7, 19 }
$119 ==> int[2] { 200, 10 }
$120 ==> int[6] { 7, 19, 283, 1283, 28, 39 }
$121 ==> int[6] { 403, 392, 4924, 293020392, 2391, 28283 }

jshell> public Foo Union(Foo obj1, Foo obj2) {
   ...>   int[] arr_a_tmp = new int[0];
   ...>   int[] arr_b_tmp = new int[0];
   ...>   Foo obj_fin = new Foo(arr_a_tmp, arr_b_tmp);
   ...>   for(int i = 0; i < obj1.a.length; i++)
   ...>     obj_fin.add(obj1.a[i], obj1.b[i]);
   ...>   for(int i = 0; i < obj2.a.length; i++)
   ...>     obj_fin.add(obj2.a[i], obj2.b[i]);
   ...>   return obj_fin;
   ...> }
|  modified method Union(Foo,Foo)

jshell> Foo objunion = Union(obj1, obj2);
objunion ==> Foo@3339ad8e

jshell> obj1.a; obj1.b; obj2.a; obj2.b; objintersect.a; objintersect.b; objunion.a; objunion.b;
   ...>
$124 ==> int[4] { 7, 19, 283, 1283 }
$125 ==> int[4] { 203, 382, 4924, 293020392 }
$126 ==> int[6] { 7, 19, 28, 39, 27, 47 }
$127 ==> int[6] { 200, 10, 2391, 28283, 2993, 2939 }
$128 ==> int[2] { 7, 19 }
$129 ==> int[2] { 200, 10 }
$130 ==> int[8] { 7, 19, 283, 1283, 28, 39, 27, 47 }
$131 ==> int[8] { 403, 392, 4924, 293020392, 2391, 28283, 2993, 2939 }

jshell>