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Commit b1468ab

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heap
1 parent 44e2f10 commit b1468ab

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6 files changed

+224
-3
lines changed

6 files changed

+224
-3
lines changed
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package geeksForGeeks.binarySearchTree;
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// Java implementation of Min Heap
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public class MinHeap {
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private int[] Heap;
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private int size;
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private int maxsize;
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private static final int FRONT = 1;
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public MinHeap(int maxsize)
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{
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this.maxsize = maxsize;
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this.size = 0;
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Heap = new int[this.maxsize + 1];
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Heap[0] = Integer.MIN_VALUE;
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}
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// Function to return the position of
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// the parent for the node currently
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// at pos
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private int parent(int pos)
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{
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return pos / 2;
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}
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// Function to return the position of the
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// left child for the node currently at pos
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private int leftChild(int pos)
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{
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return (2 * pos);
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}
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// Function to return the position of
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// the right child for the node currently
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// at pos
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private int rightChild(int pos)
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{
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return (2 * pos) + 1;
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}
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// Function that returns true if the passed
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// node is a leaf node
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private boolean isLeaf(int pos)
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{
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if (pos >= (size / 2) && pos <= size) {
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return true;
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}
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return false;
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}
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// Function to swap two nodes of the heap
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private void swap(int fpos, int spos)
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{
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int tmp;
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tmp = Heap[fpos];
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Heap[fpos] = Heap[spos];
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Heap[spos] = tmp;
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}
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// Function to heapify the node at pos
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private void minHeapify(int pos)
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{
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// If the node is a non-leaf node and greater
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// than any of its child
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if (!isLeaf(pos)) {
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if (Heap[pos] > Heap[leftChild(pos)]
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|| Heap[pos] > Heap[rightChild(pos)]) {
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// Swap with the left child and heapify
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// the left child
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if (Heap[leftChild(pos)] < Heap[rightChild(pos)]) {
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swap(pos, leftChild(pos));
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minHeapify(leftChild(pos));
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}
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// Swap with the right child and heapify
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// the right child
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else {
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swap(pos, rightChild(pos));
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minHeapify(rightChild(pos));
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}
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}
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}
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}
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// Function to insert a node into the heap
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public void insert(int element)
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{
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if (size >= maxsize) {
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return;
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}
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Heap[++size] = element;
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int current = size;
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while (Heap[current] < Heap[parent(current)]) {
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swap(current, parent(current));
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current = parent(current);
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}
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}
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// Function to print the contents of the heap
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public void print()
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{
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for (int i = 1; i <= size / 2; i++) {
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System.out.print(" PARENT : " + Heap[i]
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+ " LEFT CHILD : " + Heap[2 * i]
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+ " RIGHT CHILD :" + Heap[2 * i + 1]);
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System.out.println();
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}
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}
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// Function to build the min heap using
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// the minHeapify
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public void minHeap()
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{
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for (int pos = (size / 2); pos >= 1; pos--) {
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minHeapify(pos);
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}
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}
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// Function to remove and return the minimum
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// element from the heap
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public int remove()
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{
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int popped = Heap[FRONT];
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Heap[FRONT] = Heap[size--];
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minHeapify(FRONT);
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return popped;
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}
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// Driver code
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public static void main(String[] arg)
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{
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System.out.println("The Min Heap is ");
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MinHeap minHeap = new MinHeap(15);
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minHeap.insert(5);
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minHeap.insert(3);
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minHeap.insert(17);
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minHeap.insert(10);
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minHeap.insert(84);
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minHeap.insert(19);
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minHeap.insert(6);
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minHeap.insert(22);
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minHeap.insert(9);
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minHeap.minHeap();
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minHeap.print();
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System.out.println("The Min val is " + minHeap.remove());
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}
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}
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package javaConcepts.collection;
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// Java program to demonstrate working of PriorityQueue
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// The highest priority number or the smallest number would be removed by poll()
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// Technically it does auto sorting. removes element in log(n)
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import java.util.*;
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public class PriroityQueue {
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// Driver code
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public static void main(String args[])
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{
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// Creating empty priority queue
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PriorityQueue<Integer> pQueue = new PriorityQueue<Integer>();
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// Adding items to the pQueue using add()
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pQueue.add(30);
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pQueue.add(10);
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pQueue.add(20);
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pQueue.add(2);
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pQueue.add(400);
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// Printing the most priority element
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System.out.println("Head value using peek function:" + pQueue.peek());
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// Printing all elements
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System.out.println("The queue elements:");
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Iterator itr = pQueue.iterator();
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while (itr.hasNext())
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System.out.println(itr.next());
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// Removing the top priority element (or head) and
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// printing the modified pQueue using poll()
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pQueue.poll();
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System.out.println("After removing top priority element "
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+ "with poll function:");
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Iterator<Integer> itr2 = pQueue.iterator();
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while (itr2.hasNext())
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System.out.println(itr2.next());
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// Removing 30 using remove()
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pQueue.remove(30);
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System.out.println("after removing 30 with"
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+ " remove function:");
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Iterator<Integer> itr3 = pQueue.iterator();
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while (itr3.hasNext())
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System.out.println(itr3.next());
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// Check if an element is present using contains()
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boolean b = pQueue.contains(20);
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System.out.println("Priority queue contains 20 "
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+ "or not?: " + b);
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// Getting objects from the queue using toArray()
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// in an array and print the array
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Object[] arr = pQueue.toArray();
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System.out.println("Value in array: ");
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for (int i = 0; i < arr.length; i++)
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System.out.println("Value: " + arr[i].toString());
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}
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}
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package me.premaseem.datastructure.heap;
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public class MinHeap {
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}

‎src/me/premaseem/datastructure/heap/Heap.java renamed to ‎src/me/premaseem/datastructure/heap/imp1/Heap.java

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package me.premaseem.datastructure.heap;
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package me.premaseem.datastructure.heap.imp1;
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public class Heap {
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‎src/me/premaseem/datastructure/heap/Node.java renamed to ‎src/me/premaseem/datastructure/heap/imp1/Node.java

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package me.premaseem.datastructure.heap;
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package me.premaseem.datastructure.heap.imp1;
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public class Node {
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int key;

‎src/me/premaseem/datastructure/heap/Test.java renamed to ‎src/me/premaseem/datastructure/heap/imp1/Test.java

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package me.premaseem.datastructure.heap;
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package me.premaseem.datastructure.heap.imp1;
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public class Test {
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Heap heap = new Heap(20);

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