Create heapSort.java

sortingAlgo/heapSort/heapSort.java

@@ -0,0 +1,79 @@
+import java.util.*;
+import java.io.*;
+import java.lang.*;
+
+public class HeapSort 
+{   
+    // building the heap
+	public void buildheap(int arr[],int n){
+        for (int i = n / 2 - 1; i >= 0; i--) 
+		    heapify(arr, n, i);
+    }
+
+
+
+	public void sort(int arr[]) 
+	{ 
+		int n = arr.length; 
+
+		buildheap(arr,n); 
+        // One by one extract an element from heap
+		for (int i=n-1; i>0; i--) 
+		{ 
+
+			int temp = arr[0]; 
+			arr[0] = arr[i]; 
+			arr[i] = temp; 
+            // call max heapify
+			heapify(arr, i, 0); 
+		} 
+	} 
+
+
+    // To heapify a subtree rooted with node i 
+    void heapify(int arr[], int N, int i)
+    {
+        int largest = i; // Initialize largest as root
+        int l = 2 * i + 1; // left = 2*i + 1
+        int r = 2 * i + 2; // right = 2*i + 2
+
+        // If left child is larger than root
+        if (l < N && arr[l] > arr[largest])
+            largest = l;
+
+        // If right child is larger than largest so far
+        if (r < N && arr[r] > arr[largest])
+            largest = r;
+
+        // If largest is not root
+        if (largest != i) {
+            int swap = arr[i];
+            arr[i] = arr[largest];
+            arr[largest] = swap;
+
+            // Recursively heapify the affected sub-tree
+            heapify(arr, N, largest);
+        }
+    }
+    // function to print array of size n
+	static void printArray(int arr[]) 
+	{ 
+		int n = arr.length; 
+		for (int i=0; i<n; ++i) 
+			System.out.print(arr[i]+" "); 
+		System.out.println(); 
+	} 
+
+
+	public static void main(String args[]) 
+	{ 
+		int arr[] = {25, 4, 13, 84, 35, 7}; 
+		int n = arr.length; 
+
+		HeapSort arrnew = new HeapSort(); 
+		arrnew.sort(arr); 
+
+		System.out.println("Sorted array is"); 
+		printArray(arr); 
+	} 
+}