Run ID:76748

提交时间:2024-06-02 17:21:28

#include<bits/stdc++.h> using namespace std; int main() { int n; cin >> n; int a[n + 1]; a[1] = 1; for(int i = 2;1 <= n;i++){ a[i] = a[i-1] * 2; } int sum = 0;for(int i = 1;i <= n;i++){ sum += a[i]; } cout<<sum; return 0; }