Create QuickSort.java

JAVA/QuickSort.java

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+//program to  sort an array of given integers using Quick sort Algorithm
+
+import java.util.Arrays;
+public class QuickSort {
+
+    private int temp_array[];
+    private int len;
+
+    public void sort(int[] nums) {
+
+        if (nums == null || nums.length == 0) {
+            return;
+        }
+        this.temp_array = nums;
+        len = nums.length;
+        quickSort(0, len - 1);
+    }
+     private void quickSort(int low_index, int high_index) {
+
+        int i = low_index;
+        int j = high_index;
+        // calculate pivot number 
+        int pivot = temp_array[low_index+(high_index-low_index)/2];
+        // Divide into two arrays
+        while (i <= j) {
+               while (temp_array[i] < pivot) {
+                i++;
+            }
+            while (temp_array[j] > pivot) {
+                j--;
+            }
+            if (i <= j) {
+                exchangeNumbers(i, j);
+                //move index to next position on both sides
+                i++;
+                j--;
+            }
+        }
+        // call quickSort() method recursively
+        if (low_index < j)
+            quickSort(low_index, j);
+        if (i < high_index)
+            quickSort(i, high_index);
+    }
+
+    private void exchangeNumbers(int i, int j) {
+        int temp = temp_array[i];
+        temp_array[i] = temp_array[j];
+        temp_array[j] = temp;
+    }
+
+     // Method to test above
+    public static void main(String args[])
+    {
+        QuickSort ob = new QuickSort();
+        int nums[] = {7, -5, 3, 2, 1, 0, 45};
+        System.out.println("Original Array:");
+        System.out.println(Arrays.toString(nums));
+        ob.sort(nums);
+        System.out.println("Sorted Array");
+        System.out.println(Arrays.toString(nums));
+    }
+}