Submission #229355

#	Time	Username	Problem	Language	Result	Execution time	Memory
229355		fedoseevtimofey	Bulldozer (JOI17_bulldozer)	C++14	0 / 100	10 ms	1024 KiB

bulldozer

#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <deque>
#include <stack>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <cstring>
#include <cmath>
#include <cstdlib>
#include <algorithm>
#include <random>
#include <iomanip>
#include <functional>
#include <cassert>

using namespace std;

typedef long long ll;
typedef long double ld;

struct point {
  int x, y;
  point(int x, int y) : x(x), y(y) {}
  point(int x) : x(x), y(x) {}
  point() : x(0), y(0) {}
  point operator -(const point &p) const {
    return point(x - p.x, y - p.y);
  }
  ll operator *(const point &p) const {
    return (ll)x * p.y - (ll)y * p.x;
  }
  int type() const {
    return y > 0 || (y == 0 && x > 0);
  }
  bool operator ==(const point &p) const {
    return x == p.x && y == p.y;
  }
  bool operator <(const point &b) const {
    const point &a = *this;
    if (a.type() != b.type()) {
      return a.type() < b.type();
    }
    return a * b > 0;
  }
};

int main() {
  ios_base::sync_with_stdio(false); cin.tie(0);
#ifdef LOCAL
  freopen("input.txt", "r", stdin);
#endif
  int n;
  cin >> n;
  map <pair <int, int>, ll> cost;
  for (int i = 0; i < n; ++i) {
    int x, y, w;
    cin >> x >> y >> w;
    cost[{x, y}] += w;
  }
  n = cost.size();
  vector <point> a(n); vector <int> w(n);
  {
    int id = 0;
    for (auto it = cost.begin(); it != cost.end(); ++it, ++id) {
      a[id] = point((it->first).first, (it->first).second);
      w[id] = it->second;
    }
  }
  vector <pair <ld, pair <int, int>>> dir;
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < n; ++j) {
      if (i != j) dir.emplace_back(atan2(a[j].y - a[i].y, a[j].x - a[i].x), make_pair(i, j));
    }
  }
  sort(dir.begin(), dir.end());
  vector <int> p(n);
  iota(p.begin(), p.end(), 0);
  sort(p.begin(), p.end(), [&] (int i, int j) {
    if (a[i].y != a[j].y) return a[i].y < a[j].y;
    return a[i].x > a[j].x;
  });
  vector <int> pos(n);
  for (int i = 0; i < n; ++i) pos[p[i]] = i;
  ll ans = 0;
  for (auto d : dir) {
    ll cur = 0;
    for (int i : p) {
      cur += w[i];
      cur = max(cur, 0LL);
      ans = max(ans, cur);
    }
    swap(p[pos[d.second.first]], p[pos[d.second.second]]);
    swap(pos[d.second.first], pos[d.second.second]);
  }
  cout << ans << '\n';
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 20
• Subtask 3: 0 / 35
• Subtask 4: 0 / 20
• Subtask 5: 0 / 20