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?
Note: Given n will be a positive integer.
这道题我的解法是从n=1,2,3入手,找到规律后,打代码尝试,然后就成功了
代码如下:
class Solution {
public:
int climbStairs(int n) {
if(n==0)return 0;//先分情况找规律
else if(n==1)return 1;
else if(n==2)return 2;
int r[n];
r[0]=1;
r[1]=2;
for(int i=2;i<n;i++){
r[i]=r[i-2]+r[i-1];
}
return r[n-1];
}
};