Climbing Stairs (Easy)

Description

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?

Analysis

简单dp。走到台阶的种类数只会跟它前一个或前两个有关。因为都可以一次性到达
所以dp[i]=dp[i-1]+dp[i-2]

My Solution

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//C++
class Solution {
public:
    int climbStairs(int n) {
        int dp[100];
        dp[0]=0,dp[1]=1,dp[2]=2;
        for(int i=3;i<=n;i++){
            dp[i]=dp[i-1]+dp[i-2];
        }
        return dp[n];
    }
};