recursion.cpp

// Recursive C++ program  
// to search x in array 
#include<bits/stdc++.h> 
  
using namespace std; 
  
// Recursive function to 
// search x in arr[l..r]  
int recSearch(int arr[], int l,  
              int r, int x) 
{ 
    if (r < l) 
        return -1; 
    if (arr[l] == x) 
        return l; 
    if (arr[r] == x) 
        return r; 
    return recSearch(arr, l + 1,  
                          r - 1, x); 
} 
  
// Driver Code 
int main() 
{ 
    int arr[] = {12, 34, 54, 2, 3}, i; 
    int n = sizeof(arr) / sizeof(arr[0]); 
    int x = 3; 
    int index = recSearch(arr, 0, n - 1, x); 
    if (index != -1) 
    cout << "Element " << x  
         << " is present at index "
         << index; 
    else
        cout << "Element" << x  
             << " is not present" ; 
    return 0; 
}