Climbing Stairs

You are climbing a stair case. It takes n steps to reach to the top.Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?

int climbStairs(int n) {

   if(n <= 0 )

       return 0;

    int F[35635] = {0};

    F[0] = 0;

    F[1] = 1;

    F[2] = 2;

    for(int i  = 3; i <= n; i++)

    {

        F[i] = F[i-1] + F[i-2];

    }

    

    return F[n];

}