Submission #1180557

#	Time	Username	Problem	Language	Result	Execution time	Memory
1180557		madamadam3	Catfish Farm (IOI22_fish)	C++20	0 / 100	45 ms	7028 KiB

fish

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

using namespace std;

using vi = vector<int>;
typedef long long ll;
#define sz(x) (int) (x).size()
#define all(x) (x).begin(), (x).end()
#define pb push_back

/*
  Time log:
  - first start: 1048am
  - 3/100: 1100am
  - first stop: 1128am
  - second start: 337pm
  - 
  - second end:
  - overall time used: 
*/

/*
  NxN grid of cells
  grid[c][r] = the cell at column c row r
  grid[0][r] is the westernmost point, and grid[N-1][r] is the easternmost point
  grid[c][0] = southernmost point, grid[c][N-1] northermost point

  M catfishes
  X[i], Y[i] for i < M are column and row of fish i
  W[i] = weight of fish i
  a catfish can be caught if grid[ci][ri] is empty and grid[ci-1][ri] or grid[ci+1][ri] has a pier tile
  a pier extends from grid[cP][0] to grid[cP][rP]
*/

int N, M;
vi X, Y, W;

bool cmp(int a, int b) { // compare two fish in the same col
  return Y[a] < Y[b];
}

ll max_weights(int _N, int _M, vi _X, vi _Y, vi _W) {
  N = _N; M = _M; X = _X; Y = _Y; W = _W;

  // subtask 2: x[i] <= 1: either use everything in col0, or col1 (as using 1 means you cant use the other)
  ll c0 = 0, c1 = 0;
  vi f0, f1;
  for (int i = 0; i < M; i++) {
    // cout << "i: " << i << " x: " << X[i] << " y: " << Y[i] << " W: " << W[i] << "\n";
    if (X[i] == 0) {
      c0 += W[i];
      f0.pb(i);
    } else {
      c1 += W[i];
      f1.pb(i);
    }
  }

  sort(all(f0), cmp);
  sort(all(f1), cmp);

  int Z = sz(f0), O = sz(f1);
  // cout << "Z: " << Z << " O: " << O << "\n";
  int i = 0, j = 0;

  ll v = c1;
  ll ans = v;

  while (i < Z || j < O) {
    if (j >= O || ((i < Z) && Y[f0[i]] < Y[f1[j]])) {
      v += W[f0[i]];
      ans = max(ans, v);
      i++;
    } if (i >= Z || ((j < O) && Y[f1[j]] < Y[f0[i]])) {
      v -= W[f1[j]];
      j++;
    } else {
      break;
    }
  }

  return ans;
}

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