제출 #922356

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
922356		Ludissey	메기 농장 (IOI22_fish)	C++17	35 / 100	1115 ms	2097152 KiB

fish

#include "fish.h"
#include <bits/stdc++.h>
#define int long long
using namespace std;
vector<vector<int>> a;
vector<vector<int>> fsh;
vector<vector<int>> prfx;
vector<vector<int>> possprfx;
 
vector<vector<vector<int>>> memo;
int N,M;
//x N possible
//last N possible negatif et pas negatif
//big 3 possible
int dp(int x, int last, int big){
  if(memo[x][last][big]!=-1) return memo[x][last][big];
  if(x==N) {
    return 0;
  }
  int mx = 0;
  for (auto i:fsh[x]) //O(3)
  {
    if(i>last&&big==0) continue;
    int c=0;
    if(i==0) {
      if(big!=2) c=dp(x+1, last, 1+(last>0));
      else c=dp(x+1, 0, 1);
    }
    else c+=dp(x+1, i, (i>last));

    if(i==0&&last>0) {
      if(big<2) c+=prfx[x][last-1];
    }
    else if(last>i&&big<2) {
      c+=prfx[x][last-1]-prfx[x][i-1];
    }
    else if(i>last&&x>0){
      int ng=0;
      if(last>0) ng=prfx[x-1][last-1];
      c+=prfx[x-1][i-1]-ng;
    }
    mx=max(c, mx);
  }
  //cerr<<x << " " << last << " " << big << " = " << mx <<  "\n";
  return memo[x][last][big]=mx;
}
 
long long max_weights(signed n, signed m, std::vector<signed> X, std::vector<signed> Y, std::vector<signed> W) {
  N=n; M=m; 
  fsh.resize(N+1,vector<int>(1,0));
  prfx.resize(N+1, vector<int>(N+1,0));
  possprfx.resize(N+1, vector<int>(N+1,0));
  memo.resize(N+1, vector<vector<int>>(2*(N+1), vector<int>(3,-1)));
  a.resize(N+1, vector<int>((N+1), 0));
  for (int i = 0; i < M; i++){
    a[X[i]][Y[i]] = W[i];
    fsh[X[i]+1].push_back(Y[i]+1);
    if(X[i]>0) fsh[X[i]-1].push_back(Y[i]+1);
  }
  for (int i = 0; i < N; i++) sort(fsh[i].begin(),fsh[i].end()); // N log  N
  for (int i = 0; i < N; i++) //N*N
  {
    for (int j = 0; j < N; j++)
    {
      prfx[i][j]=a[i][j];
      if(j>0) prfx[i][j]+=prfx[i][j-1];
    }
  }
  for (int i = 0; i < N; i++) //N*N
  {
    int mxIndx=-1;
    int mx=0;
    //decrease
    for (int j = 0; j < N; j++)
    {
      if(j>0) possprfx[i][j]=possprfx[i][j-1];
      possprfx[i][j]-=a[i][j];
      if(i<N-1) possprfx[i][j]+=a[i+1][j];
      if(possprfx[i][j]>=mx) { mxIndx=j; mx=possprfx[i][j]; }
    }
    fsh[i].push_back(mxIndx+1);
    mxIndx=-1;
    mx=0;
    //increase
    for (int j = 0; j < N; j++)
    {
      if(j>0) possprfx[i][j]=possprfx[i][j-1];
      if(i>0) possprfx[i][j]+=a[i-1][j];
      if(possprfx[i][j]>mx) { mxIndx=j; mx=possprfx[i][j]; }
    }
    fsh[i].push_back(mxIndx+1);
  }
 
  int p=dp(0,0,1); //(N*2N*2*N) (300*600*300*2) (108.000.000)
  return p;
}

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• Subtask 2: 0 / 6
• Subtask 3: 0 / 9
• Subtask 4: 14 / 14
• Subtask 5: 21 / 21
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