제출 #229413

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
229413		fedoseevtimofey	Bulldozer (JOI17_bulldozer)	C++14	75 / 100	1087 ms	33932 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;	
 	
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 &a, const point &b) {	
  if (a.type() != b.type()) {	
    return a.type() < b.type();	
  }	
  return a * b > 0;	
}	
 	
const ll Inf = 1e18;	
 	
struct Node {	
  ll sum, best, max_pref, max_suf;	
  Node() {	
    sum = 0;	
    best = 0 ;	
    max_pref = max_suf = -Inf;	
  }	
  Node(ll x) {	
    sum = x;	
    best = max(x, 0LL);	
    max_pref = max(0LL, x);	
    max_suf = max(0LL, x);	
  }	
  Node operator +(const Node &other) const {	
    Node res;	
    res.best = max(best, other.best);	
    res.best = max(res.best, max_suf + other.max_pref);	
    res.sum = sum + other.sum;	
    res.max_pref = max(max_pref, sum + other.max_pref);	
    res.max_suf = max(other.max_suf, other.sum + max_suf);	
    return res;	
  }	
};	
 	
const int N = 4096;	
Node t[2 * N];	
 	
int n;	
 	
void modify(int id, ll val) {	
  t[N + id] = Node(val);	
  for (int v = (N + id) / 2; v >= 1; v /= 2) {	
    t[v] = t[2 * v] + t[2 * v + 1];	
  }	
}	
 
int main() {	
  ios_base::sync_with_stdio(false); cin.tie(0);	
#ifdef LOCAL	
  freopen("input.txt", "r", stdin);	
#endif	
  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 <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;	
  vector <pair <point, pair <int, int>>> dir;	
  for (int i = 0; i < n; ++i) {	
    for (int j = i + 1; j < n; ++j) {	
      if (pos[i] < pos[j]) dir.emplace_back(a[i] - a[j], make_pair(i, j));	
      else dir.emplace_back(a[j] - a[i], make_pair(i, j));
    }	
  }	
  sort(dir.begin(), dir.end());	
  for (int i = 0; i < n; ++i) {	
    modify(pos[i], w[i]);	
  }	
  ll ans = t[1].best;	
  point lst; bool fnd = false;
  for (auto d : dir) {	
    int i = d.second.first, j = d.second.second;	
    modify(pos[i], w[j]);	
    modify(pos[j], w[i]);	
    swap(pos[i], pos[j]);	
    if (fnd == false || lst < d.first) ans = max(ans, t[1].best);	
    fnd = true;
    lst = d.first;
  }	
 	
  cout << ans << '\n';	
}

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