题解 | #N阶楼梯上楼问题#

#include<cstdio>
using namespace std;
int DP[100];
int feibo3(int n) {
    DP[1] = 1;
    DP[2] = 2;
    for (int i = 3 ; i <= n ; ++i) {
        DP[i] = DP[i - 1] + DP[i - 2];
    }
    return DP[n];
}
int main() {
    int n;
    while (scanf("%d", &n) != EOF) {
        printf("%d\n", feibo3(n));
    }
}