Submission #785470

#	Time	Username	Problem	Language	Result	Execution time	Memory
785470		thimote75	메기 농장 (IOI22_fish)	C++17	37 / 100	1076 ms	49908 KiB

fish

#include "fish.h"

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

using num   = long long;
using idata = vector<int>;
using igrid = vector<idata>;
using ndata = vector<num>;
using ngrid = vector<ndata>;
using nmap  = map<int, num>;

const num  INF = 1e18;
const num NINF = -INF;

template <typename U, typename V>
struct MapCumul {
  map<U, V> s;
  V d;
  MapCumul (map<U, V> &m, V start) {
    V h = start;
    d = start;

    for (const auto &X : m) {
      h += X.second;

      s.insert({ X.first, h });
    }
  }
  V get (U x) {
    auto it = s.upper_bound(x);
    if (it == s.begin()) return d;

    it --;
    return (*it).second;
  }
};

struct LocalResult {
  int N;
  map<int, num> ascend, descend;
  // ascend[0] = descend[0]
  // ascend[i] => ascend[j] ifof i < j
  // descend[i] => descend[j] ifof i > j

  LocalResult (int _N) {
    N = _N;

    ascend.insert({ 0, 0 });
  }

  LocalResult next (nmap &weights) {
    LocalResult next(N);

    MapCumul<int, num> cumul(weights, 0);

    vector<int> positions = { 0 };
    for (const auto &data : weights) {
      if (positions[positions.size()] + 1 != data.first)
        positions.push_back(data.first - 1);
      positions.push_back(data.first);
    }

    if (positions[positions.size() - 1] != N)
      positions.push_back(N);

    for (int i = 1; i <= positions.size(); i ++) {
      num mx  = NINF;
      int pos = positions[i];
      num cml = cumul.get(pos);
      for (const auto &ascend_data : ascend) {
        if (ascend_data.first > pos) break ;

        int pas = ascend_data.first;
        num vas = ascend_data.second;

        mx = max(mx, vas - cumul.get(pas) + cml);
      }

      for (const auto &descend_data : descend) {
        int qps = max(pos, descend_data.first);

        mx = max(mx, descend_data.second + cumul.get(qps));
      }

      next.ascend.insert({ pos, mx });
    }

    num opt_d_pc = NINF;
    for (int i = positions.size() - 1; i >= 0; i --) {
      int pos = positions[i];
      num cml = cumul.get(pos);
      num mx  = NINF;

      for (const auto &descend_data : descend) {
        if (descend_data.first < pos) continue ;

        mx = max(mx, descend_data.second - cml + cumul.get(descend_data.first));
      }

      next.descend.insert({ pos, mx });
    }

    for (const auto &ascend_data : ascend) {
      int pos = ascend_data.first;
      auto it = next.descend.find(pos);
      num res = ascend_data.second;
      if (it != next.descend.end()) {
        const auto f = *it;
        res = max(res, f.second);
        next.descend.erase(pos);
      }
      next.descend.insert({ pos, res });
    }

    return next;
  }
};

ndata cumul (ndata &arr) {
  ndata res (arr.size() + 1, 0);

  for (int i = 0; i < arr.size(); i ++)
    res[i + 1] = res[i] + arr[i];
  
  return res;
}

num max_weights(int N, int M, idata X, idata Y, idata W) {
  LocalResult result (N);

  vector<map<int, num>> grid(N + 1);
  for (int i = 0; i < M; i ++)
    grid[X[i] + 1].insert({ Y[i] + 1, W[i] });

  num res = NINF;
  for (int i = 0; i <= N; i ++) {
    result = result.next( grid[i] );

    if (i == N - 1) {
      for (const auto &u : result.ascend) res = max(res, u.second);
    }
  }
  for (const auto &u : result.descend) res = max(res, u.second);

  return res;
}

Compilation message (stderr)

fish.cpp: In member function 'LocalResult LocalResult::next(nmap&)':
fish.cpp:67:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   67 |     for (int i = 1; i <= positions.size(); i ++) {
      |                     ~~^~~~~~~~~~~~~~~~~~~
fish.cpp:89:9: warning: unused variable 'opt_d_pc' [-Wunused-variable]
   89 |     num opt_d_pc = NINF;
      |         ^~~~~~~~
fish.cpp: In function 'ndata cumul(ndata&)':
fish.cpp:123:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  123 |   for (int i = 0; i < arr.size(); i ++)
      |                   ~~^~~~~~~~~~~~

• 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