Merge pull request deutranium#192 from K-u-n-a-l-c/patch-4

Create heapsort.java

Author: deutranium

sortingAlgo/heapSort/heapsort.java

@@ -0,0 +1,72 @@
+
+
+public class HeapSort {
+  
+    
+    void heapify(int arr[], int n, int i) {
+      int max = i; //Initialize max as root
+      int leftChild = 2 * i + 1;
+      int rightChild = 2 * i + 2;
+  
+      //If left child is greater than root
+      if (leftChild < n && arr[leftChild] > arr[max])
+        max = leftChild;
+  
+      //If right child is greater than max
+      if (rightChild < n && arr[rightChild] > arr[max])
+        max = rightChild;
+  
+      //If max is not root
+      if (max != i) {
+        int swap = arr[i];
+        arr[i] = arr[max];
+        arr[max] = swap;
+
+        //heapify the affected sub-tree recursively
+        heapify(arr, n, max);
+      }
+    }
+    
+    public void sort(int arr[]) {
+      int n = arr.length;
+  
+      //Rearrange array (building heap)
+      for (int i = n / 2 - 1; i >= 0; i--) {
+        heapify(arr, n, i);
+      }
+  
+      //Extract elements from heap one by one
+      for (int i = n - 1; i >= 0; i--) {
+        //Current root moved to the end
+        int tmp = arr[0];
+        arr[0] = arr[i];
+        arr[i] = tmp;
+      //calling max heapify on the heap reduced
+        heapify(arr, i, 0);
+      }
+    }
+  
+  
+    //print size of array n using utility function
+    static void display(int arr[]) {
+      int n = arr.length;
+      for (int i = 0; i < n; ++i)
+        System.out.print(arr[i] + " ");
+      System.out.println();
+    }
+  
+    //Driver code
+    public static void main(String args[]) {
+      int arr[] = {11, 34, 9, 5, 16, 10};
+  
+      HeapSort hs = new HeapSort();
+      System.out.println("Original array:");
+      display(arr);
+	  hs.sort(arr);
+  
+      System.out.println("Sorted array:");
+      display(arr);
+    }
+  }
+
+