Climbing Stairs

斐波那契数列

 

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