[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?

爬台阶，你每次可以上一层或者两层，问上n层你共有多少何种方法

f(n)=f(n-1)+f(n-2)

动规，记得保存n-1和n-2的结果，直接使用递归会超时

AC代码

class Solution {

public:

int climbStairs(int n) {

int count[n+1];

count[0]=0;

count[1]=1;

count[2]=2;

if(n==1)

return 1;

if(n==2)

return 2;

for(int i=3;i<=n;++i)

count[i]=count[i-1]+count[i-2];

return count
;

}

};

其他Leetcode题目AC代码：https://github.com/PoughER/leetcode