题解 | #跳台阶扩展问题#

#include<iostream>
using namespace std;
int main()
{
    int dp[41] = {0},n,sum = 0;
    cin >> n;
    dp[1] = 1;
    dp[2] = 2;
    for(int i = 3;i <= n;++i){
        for(int j = 1;j < i;++j)
            dp[i] += dp[j];
        dp[i] += 1;
    }
    cout << dp[n];
}