Submission #628267

#	Time	Username	Problem	Language	Result	Execution time	Memory
628267		600Mihnea	Catfish Farm (IOI22_fish)	C++17	37 / 100	1096 ms	68544 KiB

fish

#include "fish.h"

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

void maxup(ll &a, ll b) {
  a = max(a, b);
}

long long max_weights(int n, int cnt_fish, std::vector<int> XX, std::vector<int> YY, std::vector<int> WW) {
  n += 7;

  vector<set<int>> interestingSet(n);
  vector<vector<int>> interesting(n);
  vector<vector<vector<ll>>> dp(2, vector<vector<ll>> (n));
  vector<vector<ll>> both(n);
  vector<ll> dp_zero(n, 0LL);
  vector<vector<pair<int, ll>>> pe(n);

  assert((int) XX.size() == cnt_fish);
  assert((int) YY.size() == cnt_fish);
  assert((int) WW.size() == cnt_fish);


  for (int i = 0; i < cnt_fish; i++) {
    int x = XX[i] + 5, y = YY[i] + 1, w = WW[i];
    pe[x].push_back({y, w});
    vector<int> xs = {x - 1, x + 1};
    for (auto &i : xs) {
      interestingSet[i].insert(y);
    }
  }

  for (int x = 0; x < n; x++) {
    interestingSet[x].insert(0);
    for (auto &y : interestingSet[x]) {
      interesting[x].push_back(y);
    }
    dp[0][x].resize((int) interesting[x].size(), 0LL);
    dp[1][x].resize((int) interesting[x].size(), 0LL);
    both[x].resize((int) interesting[x].size(), 0LL);

    sort(pe[x].begin(), pe[x].end());
    ll sum = 0;
    for (auto &it : pe[x]) {
      sum += it.second;
      it.second = sum;
    }
  }

  function<ll(int, int)> get = [&] (int x, int y) {
    if (x == n) {
      return 0LL;
    }
    assert(0 <= x && x < n);
    assert(0 <= y && y < n);
    ll sol = 0;
    int low = 0, high = (int) pe[x].size() - 1;

    while (low <= high) {
      int mid = (low + high) / 2;
      if (pe[x][mid].first <= y) {
        sol = pe[x][mid].second;
        low = mid + 1;
      } else {
        high = mid - 1;
      }
    }

    return sol;
  };


  for (int i = 5; i < n - 2; i++) {
    {
      maxup(dp_zero[i], dp_zero[i - 1]);
      for (int ant_j = 0; ant_j < (int) interesting[i - 1].size(); ant_j++) {
        int h2 = interesting[i - 1][ant_j];
        maxup(dp_zero[i], both[i - 1][ant_j]);
      }
    }
    {
      int q = 0, w = 0;
      for (int j = 0; j < (int) interesting[i].size(); j++) {
        int h = interesting[i][j];
        while (q < (int) interesting[i - 2].size() && interesting[i - 2][q] < h) {
          q++;
        }
        while (w < (int) interesting[i - 1].size() && interesting[i - 1][w] < h) {
          w++;
        }
        ll dp_ant0 = 0;
        maxup(dp_ant0, dp_zero[i - 2] + get(i - 1, h) + get(i + 1, h));
        for (int ant_j = 0; ant_j < (int) interesting[i - 2].size(); ant_j++) {
          int h2 = interesting[i - 2][ant_j];
          if (h2 >= h) {
            assert(ant_j >= q);
            maxup(dp_ant0, both[i - 2][ant_j] + (get(i - 1, h) - get(i - 1, h2)) + get(i + 1, h));
          } else {
            assert(ant_j < q);
            maxup(dp_ant0, both[i - 2][ant_j] + get(i + 1, h));
          }
        }
        maxup(dp[0][i][j], dp_ant0);
        maxup(dp[1][i][j], dp_ant0);
        for (int ant_j = 0; ant_j < (int) interesting[i - 1].size(); ant_j++) {
          int h2 = interesting[i - 1][ant_j];
          if (h2 >= h) {
            assert(ant_j >= w);
            maxup(dp[0][i][j], both[i - 1][ant_j] - get(i, h) + get(i + 1, h));
          } else {
            assert(ant_j < w);
            maxup(dp[1][i][j], dp[1][i - 1][ant_j] - get(i, h2) + (get(i - 1, h) - get(i - 1, h2)) + get(i + 1, h));
          }
        }
        both[i][j] = max(dp[0][i][j], dp[1][i][j]);
      }
    }
  }
  ll sol = 0;

  for (int i = 0; i < n; i++) {
    maxup(sol, dp_zero[i]);
    for (int j = 0; j < (int) interesting[i].size(); j++) {
      maxup(sol, both[i][j]);
    }
  }

  return sol;
}

Compilation message (stderr)

fish.cpp: In function 'long long int max_weights(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
fish.cpp:81:13: warning: unused variable 'h2' [-Wunused-variable]
   81 |         int h2 = interesting[i - 1][ant_j];
      |             ^~

• Subtask 1: 0 / 3
• Subtask 2: 0 / 6
• Subtask 3: 9 / 9
• Subtask 4: 14 / 14
• Subtask 5: 0 / 21
• Subtask 6: 0 / 17
• Subtask 7: 14 / 14
• Subtask 8: 0 / 16