문제
풀이
#include <iostream>
using namespace std;
bool solve(void) {
int n; cin >> n;
if (n == 0) return false;
long long ans = 1;
int i = n+1, j = 2;
while (i <= 2*n || j <= n+1) {
if (i <= 2*n) ans *= i++;
if (j <= n+1 && ans % j == 0) ans /= j++;
}
cout << ans << "\n";
return true;
}
int main(void) {
ios::sync_with_stdio(false);
cin.tie(nullptr);
while (solve());
return 0;
}