BOJ 30143 - Cookie Piles [C++]

문제

링크

풀이

#include <iostream>
using namespace std;
 
void solve(void) {
  int n, a, d; cin >> n >> a >> d;
 
  cout << n * (2 * a + (n - 1) * d) / 2 << "\n";
}
 
int main(void) {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
 
  int t; cin >> t;
  while (t--) solve();
  return 0;
}