Submission #1027717

#	Time	Username	Problem	Language	Result	Execution time	Memory
1027717		NeroZein	Catfish Farm (IOI22_fish)	C++17	40 / 100	1069 ms	2097152 KiB

fish

#include "fish.h"
#include <bits/stdc++.h>

using namespace std;

int n; 
vector<vector<long long>> b;
vector<vector<long long>> nxt;
vector<vector<long long>> pre;
vector<vector<vector<long long>>> dp;
vector<vector<pair<int, int>>> in_col;

long long bt(int col, int prev, int cur) {
  if (col == n) {
    return 0; 
  }
  long long& ret = dp[col][prev][cur];
  if (ret != -1) {
    return ret; 
  }
  ret = 0; 
  if (col == 0) {
    for (int i = 0; i < (int) in_col[col + 1].size(); ++i) {
      long long w = max(0LL, pre[col + 1][i] - b[col][cur]);
      ret = max(ret, bt(col + 1, cur, i) + w);
    }
  } else if (col == n - 1) {
    ret = max(0LL, nxt[col - 1][prev] - b[col][cur]);
  } else {
    for (int i = 0; i < (int) in_col[col + 1].size(); ++i) {
      long long w = max(0LL, max(pre[col + 1][i], nxt[col - 1][prev]) - b[col][cur]);
      ret = max(ret, bt(col + 1, cur, i) + w);
    }
  }
  return ret; 
}

long long max_weights(int N, int M, vector<int> X, vector<int> Y, vector<int> W) {
  n = N;
  in_col.resize(N);
  for (int i = 0; i < M; ++i) {
    in_col[X[i]].push_back({Y[i], W[i]});
  }
  for (int i = 0; i < N; ++i) {
    sort(in_col[i].begin(), in_col[i].end());
    in_col[i].push_back({N, 0});
  }
  dp.resize(N);
  dp[0].resize(1);
  dp[0][0].assign(in_col[0].size(), -1);
  for (int i = 1; i < N; ++i) {
    dp[i].resize(in_col[i - 1].size());
    for (int j = 0; j < (int) in_col[i - 1].size(); ++j) {
      dp[i][j].assign(in_col[i].size(), -1);
    }
  }
  pre.resize(N);
  for (int col = 1; col < N; ++col) {
    pre[col].resize(in_col[col].size());
    for (int i = 0; i < (int) in_col[col].size(); ++i) {
      int ptr = 0; 
      long long sum = 0; 
      while (ptr < (int) in_col[col - 1].size() && in_col[col - 1][ptr].first < in_col[col][i].first) {
        sum += in_col[col - 1][ptr].second; 
        ptr++; 
      }
      pre[col][i] = sum; 
    }
  }
  nxt.resize(N);
  for (int col = 0; col < N - 1; ++col) {
    nxt[col].resize(in_col[col].size());
    for (int i = 0; i < (int) in_col[col].size(); ++i) {
      int ptr = 0;
      long long sum = 0;
      while (ptr < (int) in_col[col + 1].size() && in_col[col + 1][ptr].first < in_col[col][i].first) {
        sum += in_col[col + 1][ptr].second;
        ptr++;
      }
      nxt[col][i] = sum; 
    }
  }
  b.resize(N);
  for (int col = 0; col < N; ++col) {
    b[col].resize((int) in_col[col].size());
    for (int i = 1; i < (int) in_col[col].size(); ++i) {
      b[col][i] = b[col][i - 1] + in_col[col][i - 1].second; 
    }
  }
  long long ans = 0;
  //ans = bt(0, 0, 0);  
  for (int i = 0; i < (int) in_col[0].size(); ++i) {
    ans = max(ans, bt(0, 0, i));
  }
  return ans; 
}

• Subtask 1: 3 / 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