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:

1 2 3 4 5 .....

1 2 3 5 8 .....

通过分析可以得到，其实就是一个斐波拉契数列

代码如下(已通过leetcode)

public class Solution {

public int climbStairs(int n) {

int[] a= new int
;

if(n==1) return 1;

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];

}

}