题解 | #N阶楼梯上楼问题#

#include<iostream>
using namespace std;

int main(){
	int n;
	while(cin >> n){
		int dp[n + 1];
		dp[0] = 0, dp[1] = 1, dp[2] = 2;
		for(int i = 3; i <= n; i++){
			dp[i] = dp[i - 1] + dp[i - 2];
		}
		cout << dp[n] << endl;
	}
	return 0;
}