LeetCode Climbing Stairs

1.题目

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?

2.解决方案

class Solution {public:    int climbStairs(int n) {        if (n == 0 || n == 1) return 1;          int prev = 1;          int current = 1;          for (int i = 2; i <= n; i++) {              int temp = current + prev;              prev = current;              current = temp;          }          return current;    }};

思路：这个就是跟斐波那契数列一样的解法。用递归就太慢了。

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