제출 #1057687

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1057687		juicy	Arranging Tickets (JOI17_arranging_tickets)	C++17	100 / 100	547 ms	13728 KiB

arranging_tickets

// https://www.luogu.com.cn/article/lqa8q1lu

#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif

const int N = 2e5 + 5;

int n, m, p;
long long a[N], delta[N];
vector<array<int, 2>> g[N];

bool solve(long long cnt, long long k) {
  fill(delta + 1, delta + n + 1, 0);
  priority_queue<array<int, 2>> pq;
  long long cur = 0;
  for (int i = 1; i <= p; ++i) {
    for (auto [j, c] : g[i]) {
      if (j > p) {
        pq.push({j, c});
      }
    }
    long long need = (a[i] + cnt - k + 1) / 2;
    while (cur < need) {
      if (!pq.size()) {
        return 0;
      }
      auto [j, c] = pq.top(); pq.pop();
      long long x = need - cur;
      if (c > x) {
        c -= x;
        cur = need;
        delta[j] += x;
        pq.push({j, c});
      } else {
        delta[j] += c;
        cur += c;
      }
    }
  }
  for (int i = p + 1; i <= n; ++i) {
    cur -= delta[i];
    if (a[i] + cnt - 2 * cur > k) {
      return 0;
    }
  }
  return 1;
}

int main() {
  ios::sync_with_stdio(false); cin.tie(nullptr);

  cin >> n >> m;
  while (m--) {
    int l, r, c; cin >> l >> r >> c;
    if (l > r) {
      swap(l, r);
    }
    a[l] += c;
    a[r] -= c;
    g[l].push_back({r, c});
  } 
  for (int i = 1; i <= n; ++i) {
    a[i] += a[i - 1];
  }
  p = max_element(a + 1, a + n + 1) - a;
  auto check = [&](long long k) -> bool {
    for (auto it : {0, 1}) {
      if (solve(a[p] - k + it, k)) {
        return 1;
      }
    }
    return 0;
  };
  long long l = 1, r = a[p], res = a[p];
  while (l <= r) {
    long long md = (l + r) / 2;
    if (check(md)) {
      res = md;
      r = md - 1;
    } else {
      l = md + 1;
    }
  }
  cout << res;
  return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 35 / 35
• Subtask 3: 20 / 20
• Subtask 4: 20 / 20
• Subtask 5: 15 / 15