Merge pull request #34 from rahullo/master

 Adding binary search algorithm in cpp.

Author: shree1999

Diff for: SearchingAlgorithms/binarySearch/binarySearch.cpp

@@ -0,0 +1,56 @@
+// This is binary search algorithm in cpp. This algorithm is implemented in both way, using simple
+// while loop and recursion.
+
+#include<iostream>
+#include<stdio.h>
+
+using namespace std;
+
+
+//This function is implemented using recursion..
+void binarySearch(int arr[], int low, int high, int num){
+    int mid = (low+high)/2;
+    if(arr[mid] == num){
+        cout<<num<<" is found at index "<<mid<<endl;
+        return;
+    }
+    if(arr[mid] < num){
+        binarySearch(arr, mid+1, high, num);
+    }
+    else if(arr[mid] > num){
+        binarySearch(arr, 0, mid-1, num);
+    }
+}
+
+// This function is implemented using while loop.
+// Binary Search in C++
+void binarySearch2(int arr[], int low, int high, int num) {
+  
+	// Repeat until the pointers low and high meet each other
+  while (low <= high) {
+    int mid = low + (high - low) / 2;
+
+    if (arr[mid] == num){
+        cout<<num<<" is found at index "<<mid<<endl;
+        break;
+    }
+
+    if (arr[mid] < num){
+      low = mid + 1;
+    }
+
+    else{   
+      high = mid - 1;
+    }
+  }
+
+}
+
+int main()
+{
+    int arr[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 14, 15, 18};
+    int len = sizeof(arr)/sizeof(arr[0]);
+    binarySearch(arr, 0, len-1, 18);
+    binarySearch2(arr, 0, len-1, 15);
+    return 0;
+}