Added 3-way quick sort

Author: prince776

Algorithms/Sorting/3_way_quick_sort.cpp

@@ -0,0 +1,63 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+void swap(int &a, int &b)
+{
+	int t = a;
+	a = b;
+	b = t;
+}
+
+void partition(int a[], int low, int high, int &i, int &j)
+{
+	// To handle two elemts
+	if (high - low <= 1)
+	{
+		if (a[high] < a[low])
+			swap(a[high], a[low]);
+		i = low;
+		j = high;
+		return;
+	}
+
+	int mid = low;
+	int pivot = a[high];
+
+	while (mid <= high)
+	{
+		if (a[mid] < pivot)
+			swap(a[low++], a[mid++]);
+		else if (a[mid] == pivot)
+			mid++;
+		else if (a[mid] > pivot)
+			swap(a[mid], a[high--]);
+	}
+
+	i = low - 1;
+	j = mid;
+}
+
+void quickSort(int a[], int low, int high)
+{
+	if (low >= high)
+		return;
+	int i, j;
+
+	partition(a, low, high, i, j);
+	quickSort(a, low, i);
+	quickSort(a, j, high);
+}
+
+int main()  
+{  
+    int arr[] = {64, 25, 25, 11, 11, 12, 22, 11};  
+    int n = sizeof(arr)/sizeof(arr[0]);  
+    quickSort(arr, 0, n - 1);  
+	cout << "Sorted array: \n";  
+    for (int i = 0; i < n; i++)
+    {
+    	cout << arr[i] << " ";
+    }
+    return 0;  
+}

Algorithms/Sorting/selection_sort.cpp

@@ -33,4 +33,4 @@ int main()
     	cout << arr[i] << " ";
     }
     return 0;  
-}
+}