Merge pull request #190 from Bhavdeepq/patch-1

Create binarysearch.py

Author: Pradeepsingh61

binarysearch.py

@@ -0,0 +1,39 @@
+# Python 3 program for recursive binary search.
+# Modifications needed for the older Python 2 are found in comments.
+
+# Returns index of x in arr if present, else -1
+def binary_search(arr, low, high, x):
+
+    # Check base case
+    if high >= low:
+
+        mid = (high + low) // 2
+
+        # If 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
+        elif arr[mid] > x:
+            return binary_search(arr, low, mid - 1, x)
+
+        # Else the element can only be present in right subarray
+        else:
+            return binary_search(arr, mid + 1, high, x)
+
+    else:
+        # Element is not present in the array
+        return -1
+
+# Test array
+arr = [ 2, 3, 4, 10, 40 ]
+x = 10
+
+# Function call
+result = binary_search(arr, 0, len(arr)-1, x)
+
+if result != -1:
+    print("Element is present at index", str(result))
+else:
+    print("Element is not present in array")