LeetCode 70.爬楼梯

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