Submission #7273388

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;

int n;

int quadrant(int x, int y) {
  if (x > 0 && y >= 0) return 0;
  if (x <= 0 && y > 0) return 1;
  if (x < 0 && y >= 0) return 2;
  return 3;
}

bool cmp(pair<int, int> p, pair<int, int> q) {
  int q1 = quadrant(p.first, p.second);
  int q2 = quadrant(q.first, q.second);
  
  if (q1 != q2) return q1 < q2;
  
  if (q1 == 0 || q1 == 2) {
    p = {abs(p.first), abs(p.second)};
    q = {abs(q.first), abs(q.second)};
  } else {
    p = {abs(p.second), abs(p.first)};
    q = {abs(q.second), abs(q.first)};
  }
  
  return 1LL * p.second * q.first < 1LL * p.first * q.second;
}

int main() {
  vector<pair<int, int>> v;
  scanf("%d", &n);
  
  for (int i = 0; i < n; ++i) {
    int x, y;
    scanf("%d %d", &x, &y);
    if (x == 0 && y == 0) continue;
    
    v.emplace_back(x, y);
  }
  
  sort(v.begin(), v.end(), cmp);
  n = v.size();
  
  double ans = 0;
  for (int i = 0; i < n; ++i) {
    long long curx = 0, cury = 0;
    for (int j = 0; j < n; ++j) {
      curx += v[(i+j) % n].first;
      cury += v[(i+j) % n].second;
      
      ans = max(ans, hypot(curx, cury));
    }
  }
  
  printf("%.18lf\n", ans);
  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:32:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &n);
                  ^
./Main.cpp:36:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &x, &y);
                           ^

Judge Result