BOJ 1198 - 삼각형으로 자르기 [C++]

문제

링크

풀이

#include <algorithm>
#include <cmath>
#include <iomanip>
#include <iostream>
#include <vector>
using namespace std;
 
inline double calc(int x1, int y1, int x2, int y2, int x3, int y3) {
  return abs((x2 - x1) * (y3 - y1) - (y2 - y1) * (x3 - x1)) / 2.0;
}
 
void solve(void) {
  int n; cin >> n;
  vector<int> x(n), y(n);
  for (int i=0; i<n; i++) cin >> x[i] >> y[i];
 
  double ans = 0;
  for (int i=0; i<n-2; i++) for (int j=i+1; j<n-1; j++) for (int k=j+1; k<n; k++) {
    ans = max(ans, calc(x[i], y[i], x[j], y[j], x[k], y[k]));
  }
  cout << fixed << setprecision(10) << ans;
}
 
int main(void) {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
 
  solve();
  return 0;
}