Count no of binary strings

#1


why my test cases are failing

#2

https://ide.codingblocks.com/s/258416 this code is also not passing test case 2 n 3

#3

make it long int

#include<bits/stdc++.h>
using namespace std;



int main(){
    int t;
    cin>>t;
    while(t--){
        long int n,q=2;
        cin>>n;
        long int arr[q][n+1];
        memset(arr,0,sizeof(arr));
        //first row(i.e. 0th index) stands for 0 and second row for 1
        arr[0][1]=arr[1][1]=1;
        for(int i=2;i<=n;i++){
            arr[0][i]=arr[0][i-1]+arr[1][i-1];
            arr[1][i]=arr[0][i-1];
        }
        cout<<arr[0][n]+arr[1][n]<<endl;
    }
    

}