Given an array of length N and an integer x, you need to find and return the first index of integer x present in the array. Return -1 if it is not present in the array. First index means, the index of first occurrence of x in the input array. Do this recursively. Indexing in the array starts from 0.

PROBLEM:-

First Index of Number

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Given an array of length N and an integer x, you need to find and return the first index of integer x present in the array. Return -1 if it is not present in the array.

First index means, the index of first occurrence of x in the input array.

Do this recursively. Indexing in the array starts from 0.

Input Format :

Line 1 : An Integer N i.e. size of array
Line 2 : N integers which are elements of the array, separated by spaces
Line 3 : Integer x

Output Format :

first index or -1

Constraints :

1 <= N <= 10^3

Sample Input :

4
9 8 10 8
8

Sample Output :

1

SOLUTION:-

#include<iostream>
using namespace std;

int firstIndex(int input[], int size, int x) {
  /* Don't write main().
     Don't read input, it is passed as function argument.
     Return output and don't print it.
     Taking input and printing output is handled automatically.
  */
    if(size==0)
        return -1;
    else{
    static int i=0;
    if(input[0]==x)
        return i;
    else{
        i++;
        firstIndex(input+1,size-1,x);
    }
    }

}

int main(){
    int n;
    cin >> n;
  
    int *input = new int[n];
    
    for(int i = 0; i < n; i++) {
        cin >> input[i];
    }
    
    int x;
    
    cin >> x;
    
    cout << firstIndex(input, n, x) << endl;

}

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