From 193bee0930a9fd4270cf79c5834ad018dc6a3843 Mon Sep 17 00:00:00 2001
From: aryan raj <aryan.raj.ece20@itbhu.ac.in>
Date: Thu, 9 Sep 2021 21:35:57 -0700
Subject: [PATCH] added binary search algo in c++

---
 c++/binarysearch2.cpp | 50 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 c++/binarysearch2.cpp

diff --git a/c++/binarysearch2.cpp b/c++/binarysearch2.cpp
new file mode 100644
index 0000000..927a4e5
--- /dev/null
+++ b/c++/binarysearch2.cpp
@@ -0,0 +1,50 @@
+#include <iostream>
+using namespace std;
+
+int binarySearch(int arr[], int l , int r, int num);
+
+int main()
+{
+    int n, num;
+    cin >> n >> num;
+    int arr[n];
+    for (int i = 0; i < n; i++)
+    {
+        cin >> arr[i];
+    }
+
+    int index = binarySearch(arr, 0, n - 1, num);
+    if (index == -1)
+    {
+        cout << num << " is not present in the given array";
+    }
+
+    else
+    {
+        cout << num << " is present at index " << index + 1 << " in the array";
+    }
+
+    return 0;
+}
+int binarySearch(int arr[], int l, int r, int num)
+{
+    if (l <= r)
+    {
+        int mid = l + (r-1)/2;
+        if (arr[mid] == num)
+        {
+            return mid;
+        }
+
+        if (arr[mid] > num)
+        {
+            return binarySearch(arr, l, mid - 1, num);
+        }
+
+        if (arr[mid] < num)
+        {
+            return binarySearch(arr, mid + 1, r, num);
+        }
+    }
+    return -1;
+}