climbing-stairs.cpp

class Solution {
public:
    int climbStairs(int n) {
        if (n == 0){
            return 1;
        }
        if (n == 1){
            return 1;
        }
        vector<int> step(n+1);
        step[0] = 1;
        step[1] = 1;
        for(int i = 2 ; i <= n ; i++){
            step[i] = step[i-1] + step[i-2];
        }
        return step[n];
    }
};