PASS Week 03/24: Arrays

Problem #1:

Write a program that creates an array of 5 integer values using a for loop, 1 through
5. The iterator can be used as the values to be stored. The program should
then use a second for loop to copy those elements into a second array, but this time
you should use a for loop to enter the values into the new array backwards. The
program should then use a third for loop to print out the first array to screen on one
line, then a fourth for loop to print out the second array. The output should
resemble this:

A:  1 2 3 4 5
B:  5 4 3 2 1




/*** SKELETON CODE ***/

/*
* This program demonstrates how to copy one array to
* another array and how to make use of the iterator.
* By: L. Snedden
*/
#include <stdio.h>

int main(void)
{
	int a[5] = {0};
	int b[5] = {0};

	//FIRST LOOP GOES HERE (This one initializes the values)

	//SECOND LOOP GOES HERE (This one copies)

	//THIRD LOOP GOES HERE (This one prints the first array)

	//FOURTH LOOP GOES HERE (This one prints the second array)

	return 0;
}
























Problem #2:

Write a function that reverses the elements of an array of integers so that the last
element becomes the first, the second from last becomes second, and so forth. The
function is to reverse the elements in place, i.e., WITHOUT USING A SECOND ARRAY. You
can use a variable to hold an element temporarily. Try changing up your program to use an odd-sized
array or an even-sized array to test it out!



/*** SKELETON CODE ***/

#include <stdio.h>

//Function Prototype
void reverseArray(int[], int);

int main(void)
{
	//local declarations
	int ary[10];


	/*** INITIALIZE ARRAY VALUES HERE (Using a Loop) ***/

 	printf("Before reversal:\n");
	//Loop to Print all values
	for(int i = 0; i < 10; i++) {
	printf("Element %d is %d\n", i, ary[i]);
	}

	/*** CALL YOUR FUNCTION HERE ***/

 	printf("\nAfter reversal:\n");
	//Loop to Print values AFTER reversal
	for(int i = 0; i < 10; i++) {
	printf("Element %d is %d\n", i, ary[i]);
	}

	return 0;
}//end main

/* REVERSE ARRAY FUNCTION */
void reverseArray(int x[], int size)
{
	/*** LOOP GOES HERE ***/

	return;

}//end function

























Problem #3:

The International Standard Book Number, ISBN, is used to uniquely identify a book.
It is made of 10 digits. Write a function that tests an ISBN to see if it is valid. For an
ISBN number to be valid, the weighted sum of the 10 digits must be evenly divisible
by 11.

To determine the weighted sum, the value of each position is multiplied by its
relative position, starting from the right, and the sum of the product is determined.
Since the weighted sum modulus 11 is 0, the ISBN number is valid. Test your
function with examples, use Amazon to get valid book ISBNs if you want.

Example
ISBN: 0-07-881809-5 (assume no dashes in your function)

 Code         Weight      Value
    0             10          0
    0              9          0
    7              8         56
    8              7         56
    8              6         48
    1              5          5
    8              4         32
    0              3          0
    9              2         18
    5              1          5

  Weighted Sum is 220

  220 % 11 = 0  (Valid ISBN)




SAMPLE OUTPUT:

Enter in 10 numbers one at a time: 0
Enter in 10 numbers one at a time: 0
Enter in 10 numbers one at a time: 7
Enter in 10 numbers one at a time: 8
Enter in 10 numbers one at a time: 8
Enter in 10 numbers one at a time: 1
Enter in 10 numbers one at a time: 8
Enter in 10 numbers one at a time: 0
Enter in 10 numbers one at a time: 9
Enter in 10 numbers one at a time: 5
The weighted sum is  220
The ISBN is valid



/*** SKELETON CODE ***/

/* This program is a test driver for the ISBN
* validation function. This function tests the
* weighted sum and value to determine if the
* ISBN number is valid.
*/
#include <stdio.h>

//Function prototype
int isbnTest(int[]);

int main(void)
{
	//local declarations
	int ary[10];
	int result;

	//local statements
	//Loop to scan 10 values from user one at a time (NO DASHES)
	for(int i = 0; i < 10; i++)
	{
		printf("Enter in 10 numbers one at a time: ");
		scanf("%d", &ary[i]);
	}

	/*** CALL FUNCTION AND CHECK VALIDITY HERE ***/

	return 0;
}//end main

//ISBN TEST FUNCTION
int isbnTest(int ary[])
{
	/*** WRITE FUNCTION BODY HERE (Variables, Loop, etc) ***/

}//end fuction