riskFactor_kolokviumska

package com.example;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Map;

class MapEntry<K extends Comparable<K>,E> implements Comparable<K> {

    // Each MapEntry object is a pair consisting of a key (a Comparable
    // object) and a value (an arbitrary object).
    K key;
    E value;

    public MapEntry (K key, E val) {
        this.key = key;
        this.value = val;
    }

    public int compareTo (K that) {
        // Compare this map entry to that map entry.
        @SuppressWarnings("unchecked")
        MapEntry<K,E> other = (MapEntry<K,E>) that;
        return this.key.compareTo(other.key);
    }

    public String toString () {
        return "<" + key + "," + value + ">";
    }
}

class OBHT<K extends Comparable<K>,E> {

    // An object of class OBHT is an open-bucket hash table, containing entries
    // of class MapEntry.
    private MapEntry<K,E>[] buckets;

    // buckets[b] is null if bucket b has never been occupied.
    // buckets[b] is former if bucket b is formerly-occupied
    // by an entry that has since been deleted (and not yet replaced).

    static final int NONE = -1; // ... distinct from any bucket index.

    private static final MapEntry former = new MapEntry(null, null);
    // This guarantees that, for any genuine entry e,
    // e.key.equals(former.key) returns false.

    private int occupancy = 0;
    // ... number of occupied or formerly-occupied buckets in this OBHT.

    @SuppressWarnings("unchecked")
    public OBHT (int m) {
        // Construct an empty OBHT with m buckets.
        buckets = (MapEntry<K,E>[]) new MapEntry[m];
    }


    private int hash (K key) {
        // Translate key to an index of the array buckets.
        return Math.abs(key.hashCode()) % buckets.length;
    }


    public int search (K targetKey) {
        // Find which if any bucket of this OBHT is occupied by an entry whose key
        // is equal to targetKey. Return the index of that bucket.
        int b = hash(targetKey); int n_search=0;
        for (;;) {
            MapEntry<K,E> oldEntry = buckets[b];
            if (oldEntry == null)
                return NONE;
            else if (targetKey.equals(oldEntry.key))
                return b;
            else
            {
                b = (b + 1) % buckets.length;
                n_search++;
                if(n_search==buckets.length)
                    return NONE;

            }
        }
    }


    public void insert (K key, E val) {
        // Insert the entry <key, val> into this OBHT.
        MapEntry<K,E> newEntry = new MapEntry<K,E>(key, val);
        int b = hash(key); int n_search=0;
        for (;;) {
            MapEntry<K,E> oldEntry = buckets[b];
            if (oldEntry == null) {
                if (++occupancy == buckets.length) {
                    System.out.println("Hash tabelata e polna!!!");
                }
                buckets[b] = newEntry;
                return;
            }
            else if (oldEntry == former
                    || key.equals(oldEntry.key)) {
                buckets[b] = newEntry;
                return;
            }
            else
            {
                b = (b + 1) % buckets.length;
                n_search++;
                if(n_search==buckets.length)
                    return;

            }
        }
    }


    @SuppressWarnings("unchecked")
    public void delete (K key) {
        // Delete the entry (if any) whose key is equal to key from this OBHT.
        int b = hash(key); int n_search=0;
        for (;;) {
            MapEntry<K,E> oldEntry = buckets[b];

            if (oldEntry == null)
                return;
            else if (key.equals(oldEntry.key)) {
                buckets[b] = former;//(MapEntry<K,E>)former;
                return;
            }
            else{
                b = (b + 1) % buckets.length;
                n_search++;
                if(n_search==buckets.length)
                    return;

            }
        }
    }


    public String toString () {
        String temp = "";
        for (int i = 0; i < buckets.length; i++) {
            temp += i + ":";
            if (buckets[i] == null)
                temp += "\n";
            else if (buckets[i] == former)
                temp += "former\n";
            else
                temp += buckets[i] + "\n";
        }
        return temp;
    }


    public OBHT<K,E> clone () {
        OBHT<K,E> copy = new OBHT<K,E>(buckets.length);
        for (int i = 0; i < buckets.length; i++) {
            MapEntry<K,E> e = buckets[i];
            if (e != null && e != former)
                copy.buckets[i] = new MapEntry<K,E>(e.key, e.value);
            else
                copy.buckets[i] = e;
        }
        return copy;
    }
}

class Patient {
    String prezime;
    String opstina;
    String pozitiven;

    public Patient(){}
    public Patient(String prezime, String opstina, String pozitiven) {
        this.prezime = prezime;
        this.opstina = opstina;
        this.pozitiven = pozitiven;
    }
    public String getPrezime() {
        return this.prezime;
    }
    public String getOpstina() {
        return this.opstina;
    }
    public String getPozitiven() {
        return this.pozitiven;
    }
    public void setPrezime(String prezime) {
        this.prezime = prezime;
    }
    public void setOpstina(String opstina) {
        this.opstina = opstina;
    }
    public void setPozitiven(String pozitiven) {
        this.pozitiven = pozitiven;
    }
}

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        int n = Integer.parseInt(br.readLine());
        HashMap<Integer,Patient> patients = new HashMap<>(n);

        for (int i=0; i<n; i++) {
            String pacient = br.readLine();
            String[] pacienti = pacient.split(" ");
            String prezime = pacienti[1];
            String opstina = pacienti[0];
            String pozitiven = pacienti[2];
            Patient p = new Patient(prezime,opstina,pozitiven);
            patients.put(i, p);
        }

        String opshtina = br.readLine();
        int VKP = 0;
        int VKN = 0;
        float riskFactor;

        for (Map.Entry<Integer,Patient> curr : patients.entrySet()) {
            if (curr.getValue().opstina.equals(opshtina)) {
                if (curr.getValue().pozitiven.equals("pozitiven")) {
                    VKP++;
                } else if (curr.getValue().pozitiven.equals("negativen")) {
                    VKN++;
                }
            }
        }

        System.out.println(VKP);
        System.out.println(VKN);

        riskFactor = (float) VKP / (VKP + VKN);

        System.out.println(String.format("%.2f", riskFactor));

//        for (int i=0; i<n; i++) {
//            System.out.println(patients.get(i).prezime);
//        }
    }
}


// risk factor = vkupen broj na pozitivni / (zbir od vkupen broj pozitivni i negativi);

5
Centar Trajko pozitiven
Centar Vladislav negativen
Karpos Svetoslava pozitiven
Centar Trajan negativen
Karpos Darko pozitiven
Centar

output:
0.33