24265

문제

https://www.acmicpc.net/problem/24265

풀이

#include <iostream>
using namespace std;
typedef long long ll;

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);

	ll N; cin >> N;
	cout << (N * (N - 1)) / 2 << '\n' << 2;
}

24266

문제

https://www.acmicpc.net/problem/24266

풀이

#include <iostream>
using namespace std;
typedef long long ll;

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);

	ll N; cin >> N;
	cout << N * N * N << '\n' << 3;
}

24267

문제

https://www.acmicpc.net/problem/24267

풀이

#include <iostream>
using namespace std; 
int main(){    
    long long n;    
    cin >> n;   
    cout << (n-2)*(n-1)*n/6 << '\n' << 3;    
    return 0;
}