Submission #1180618

#	Time	Username	Problem	Language	Result	Execution time	Memory
1180618		madamadam3	Catfish Farm (IOI22_fish)	C++20	0 / 100	14 ms	5044 KiB

fish

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

using namespace std;

typedef long long ll;
using vi = vector<int>;
using vl = vector<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
  - 416pm finally stopped being stupid and got 9/100 (+6 points)
  - 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; vector<ll> 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; for (int i = 0; i < M; i++) W.pb(ll(_W[i]));

  // subtask 3: y[i] = 0 for all i, so just do a dp where DP[i][use] = max(DP[i-2][use] + W[i], DP[i-1][!use] + w[i])
  vl Weights(N+2, 0LL); for (int i = 0; i < M; i++) Weights[X[i]+1] = W[i];

  ll DP[N+1]; // 0 for use, 1 for not use
  DP[0] = 0LL;
  DP[1] = Weights[0] + Weights[2];

  for (int i = 2; i <= N; i++) {
    ll useval = Weights[i - 1] + Weights[i + 1];
    DP[i] = max(DP[i - 2] + useval - Weights[i - 1], DP[i - 1]);
  }

  return DP[N];
}

• 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