Run ID:63184

提交时间:2024-01-06 14:05:16

#include<iostream> using namespace std; int main(){ int n; cin >> n; long long a[50] = {0}; a[0] = 1; for(int i = 1 ; i <= n ; i++){ a[i] += 2*a[i-1]; } cout << a[n-1]; return 0; }