79 lines
1.7 KiB
Java
79 lines
1.7 KiB
Java
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// Class implementation of Priority-Queue using an array
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import java.util.*;
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class PriorityQueue {
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private int max_size; // To provide maximum size of Array
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private int[] arr;
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private int no_items;
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public PriorityQueue(int s){
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max_size = s;
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arr = new int[max_size];
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no_items = 0;
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}
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public void insert(int val){ //Method to insert element into Priority Queue
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int j;
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if (no_items == 0){
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arr[no_items++] = val;
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}
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else {
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for ( j=no_items-1;j>=0;j--){
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if (val<arr[j]) // To get in ascending order change to '>' operator
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{
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arr[j+1] = arr[j];
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}
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else break;
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}
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arr[j+1] = val;
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no_items++;
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}
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}
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public void remove(){ // Method to remove front element in Priority Queue
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--no_items;
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}
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public int front(){ // Method to retrieve front element
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return arr[no_items-1];
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}
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public boolean isEmpty() { // Method to check if queue is empty
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return no_items == 0;
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}
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public boolean isFull() { // Method to check if queue is full
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return no_items == max_size;
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}
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}
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class Main { // Class containing main method.
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public static void main(String[] args) {
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PriorityQueue pq = new PriorityQueue(5);
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pq.insert(23); // [23]
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pq.insert(56); // [56,23]
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pq.insert(25); // [56,25,23]
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System.out.println(pq.front()); // 56
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pq.remove(); // [25,23]
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System.out.println(pq.front()); // 25
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System.out.println(pq.isEmpty()); // False
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pq.insert(100); // [100,25,23]
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pq.insert(98); // [100,98,25,23]
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pq.insert(99); // [100,99,98,25,23]
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System.out.println(pq.front()); // 100
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System.out.println(pq.isFull()); // True
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}
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}
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