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。
http://www.waitingfy.com/archives/1602