Merge pull request #541 from Rimjhim28/patch_2

Add recursive binary search using java

binary_search/using_recursion_in_java.java

@@ -0,0 +1,46 @@
+// Java implementation of recursive Binary Search
+class BinarySearch
+{
+    // 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;
+    }
+
+    // Driver method to test above
+    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);
+    }
+}