Create binarysearch.cpp

Intermediate/binarysearch.cpp

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+// C program to implement recursive Binary Search 
+#include <stdio.h> 
+
+// A recursive binary search function. It returns 
+// location of x in given array arr[l..r] is present, 
+// otherwise -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; 
+} 
+
+int main(void) 
+{ 
+    int arr[] = { 2, 3, 4, 10, 40 }; 
+    int n = sizeof(arr) / sizeof(arr[0]); 
+    int x = 10; 
+    int result = binarySearch(arr, 0, n - 1, x); 
+    (result == -1) ? printf("Element is not present in array") 
+                   : printf("Element is present at index %d", 
+                            result); 
+    return 0; 
+}