ThreeWayQuickSort Java

Sort/Java/ThreeWayQuickSort.java

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+
+public class ThreeWayQuickSort {
+
+	public static void main(String a[]) {
+		int[] arr1 = { 9, 14, 3, 2, 43, 11, 58, 22 };
+		System.out.println("Before Sort");
+		for (int i : arr1) {
+			System.out.print(i + " ");
+		}
+		System.out.println();
+
+		sort(arr1, 0, arr1.length - 1);// sorting array using insertion sort
+
+		System.out.println("After Sort");
+		for (int i : arr1) {
+			System.out.print(i + " ");
+		}
+	}
+
+	public static void sort(int[] array, int leftIndex, int rightIndex) {
+
+		if (array.length > 1 && leftIndex < rightIndex) {
+			int[] resposta = partition(array, leftIndex, rightIndex);
+			sort(array, leftIndex, resposta[0] - 1);
+			sort(array, resposta[1] + 1, rightIndex);
+		}
+	}
+
+	private static int[] partition(int[] array, int leftIndex, int rightIndex) {
+		int j = leftIndex;
+		int k = rightIndex;
+		int nPivot = array[leftIndex];
+		int i = leftIndex;
+
+		while (i <= k) {
+			if (array[i] == (nPivot))
+				++i;
+			else if (array[i] > (nPivot))
+				swap(array, i, k--);
+			else {
+				swap(array, i++, j++);
+			}
+		}
+
+		int[] resposta = { j, k };
+		return resposta;
+	}
+
+	public static void swap(int[] array, int i, int j) {
+		if (array == null)
+			throw new IllegalArgumentException();
+
+		int temp = array[i];
+		array[i] = array[j];
+		array[j] = temp;
+	}
+}