Merge pull request #21 from Amisha-Mohapatra/binary-search-add

Binary search add

searching/README.md

@@ -18,5 +18,6 @@
 ### Java
 
 1. [Linear Search](java/linear-search.java)
+2. [Binary Search](java/binary-search.java)
 
 

searching/java/binary-search.java

@@ -0,0 +1,47 @@
+// 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); 
+    } 
+} 
+
+// For running in terminal rename this file to BinarySearch.java
+//then run the commands <javac BinarySearch.java> followed by <java BinarySearch>
+//It will generate and a BinarySearch.class file which is a file containing java bytecode that is executed by JVM.