#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?

斐波那契数列，计算迭代f(n)=f(n-1)+f(n-2)

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