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.
Example 1:
Input: 2 Output: 2 Explanation: There are two ways to climb to the top. 1. 1 step + 1 step 2. 2 steps
Example 2:
Input: 3 Output: 3 Explanation: There are three ways to climb to the top. 1. 1 step + 1 step + 1 step 2. 1 step + 2 steps 3. 2 steps + 1 step
简单的动态规划,不必多说。
代码:
class Solution {
public:
int climbStairs(int n) {
int f[n+1];
f[0]=1;
f[1]=1;
for(int i=2;i<=n;i++)
f[i]=f[i-1]+f[i-2];
return f[n];
}
};