Run ID:76754

提交时间:2024-06-02 17:23:02

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