Merge pull request sat5297#39 from ultimatecoder2/master

Created BinarySearch cpp programme

Author: sat5297

BinarySearch.cpp

@@ -0,0 +1,51 @@
+/*
+Time complexity: O(log n)
+Contributor: Deepanshu Jindal(https://github.com/ultimatecoder2)
+*/
+
+#include<bits/stdc++.h>
+using namespace std;
+
+int BinarySearch(int arr[],int low,int high,int el)
+{
+    if(low>high)
+    {
+        return -1;
+    }
+
+    int mid  = (low+high)/2;
+    if(arr[mid] == el)
+    {
+        return mid;
+    }
+    if(arr[mid]<el)
+    {
+        return BinarySearch(arr,mid+1,high,el);
+    }
+    if(arr[mid]>el)
+    {
+        return BinarySearch(arr,low,mid-1,el);
+    }
+
+}
+int main()
+{
+    int n;
+    cout<<"Enter Size of Array"<<endl;
+    cin>>n;
+    cout<<"Enter the elements of array"<<endl;
+    int arr[n];
+    for(int i=0;i<n;i++)
+        cin>>arr[i];
+    cout<<"Enter the element that you want to find"<<endl;
+    int el;
+    cin>>el;
+    int index =BinarySearch(arr,0,n-1,el);
+    if(index<0)
+        cout<<"Element is not present in the array"<<endl;
+    else
+    {
+        cout<<"Element is present at "<<index + 1<<" position"<<endl;
+    }
+    return 0;
+}