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?

class Solution {

public:
    int climbStairs(int n) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        
        // could try DP
        vector<int> dp(n,0);
        dp[0] = 1; dp[1] = 2;
        for (int i=2;i<n;i++){
            dp[i] = dp[i-1] + dp[i-2];
        }
        return dp[n-1];
    }
};