【LeetCode】70. Climbing Stairs

Problem here

Problem

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?

Solution

這題之前做過 
就是超級樓梯那條

class Solution {
public:
    int climbStairs(int n) {
        vector<int> f;
        f.push_back(1);
        f.push_back(1);
        for(int i = 2; i <= n; i++){
            f.push_back(f[i-1] + f[i-2]);
        }
        return f[n];

    }
};