Dutch flag algo

Algorithms/DutchNationalFlagAlgo.java

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+import java.util.Scanner;
+public class DutchNationalFlagAlgo
+{
+    public static void sortColors(int[] nums) {
+        int mid=0;
+        int low=0;
+        int high=nums.length - 1;
+        while(mid<=high)
+        {
+            if(nums[mid]==0)
+            {
+                int temp = nums[low];
+                nums[low] = nums[mid];
+                nums[mid] = temp;
+                mid++;
+                low++;
+            }
+            else if (nums[mid]==1)
+            {
+                mid++;
+            }
+            else
+            {
+                int temp = nums[high];
+                nums[high] = nums[mid];
+                nums[mid] = temp;
+                high--;
+            }
+        }
+    }
+	public static void main(String[] args) {
+	    Scanner sc = new Scanner(System.in);
+	    int n = sc.nextInt();
+	    int []arr = new int[n];
+	    for(int i=0;i<n;i++)
+	    {
+	        arr[i] = sc.nextInt();
+	    }
+	    sortColors(arr);
+	    for(int i=0;i<n;i++)
+	    {
+	        System.out.print(arr[i]+" ");
+	    }
+
+	}
+}

Algorithms/RecursiveBinarySearch.java

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+// Java implementation of recursive Binary Search
+class RecursiveBinarySearch {
+    // Returns index of x if it is present in arr[l..
+    // r], else return -1
+    int binarySearch(int arr[], int l, int r, int x)
+    {
+        if (r >= l) {
+            int mid = l + (r - l) / 2;
+
+            // If the element is present at the
+            // middle itself
+            if (arr[mid] == x)
+                return mid;
+
+            // If element is smaller than mid, then
+            // it can only be present in left subarray
+            if (arr[mid] > x)
+                return binarySearch(arr, l, mid - 1, x);
+
+            // Else the element can only be present
+            // in right subarray
+            return binarySearch(arr, mid + 1, r, x);
+        }
+
+        // We reach here when element is not present
+        // in array
+        return -1;
+    }
+
+
+    public static void main(String args[])
+    {
+        BinarySearch ob = new BinarySearch();
+        int arr[] = { 2, 3, 4, 10, 40 };
+        int n = arr.length;
+        int x = 10;
+        int result = ob.binarySearch(arr, 0, n - 1, x);
+        if (result == -1)
+            System.out.println("Element not present");
+        else
+            System.out.println("Element found at index " + result);
+    }
+}
+