【LeetCode】70. 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?

【思路】斐波那契数列，第n阶是由第n-1阶和n-2阶的方法求和而成。

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