Submission #858819

#	Time	Username	Problem	Language	Result	Execution time	Memory
858819		LucaIlie	Catfish Farm (IOI22_fish)	C++17	64 / 100	1091 ms	530204 KiB

fish

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

using namespace std;

const int MAX_N = 3e5 + 2;
const long long INF = 1e18;
unordered_map<int, long long> costCell[MAX_N], dp[MAX_N], dpLower[MAX_N], spX[MAX_N], maxPref1[MAX_N], maxSuf2[MAX_N], maxPref3[MAX_N];
vector <int> ys[MAX_N];

long long max_weights( int n, int m, vector <int> X, vector <int> Y, vector <int> W ) {

    for ( int i = 0; i < m; i++ ) {
        X[i]++;
        Y[i]++;
        costCell[X[i]][Y[i]] = W[i];
        ys[X[i] - 1].push_back( Y[i] );
        ys[X[i] + 1].push_back( Y[i] );
        ys[X[i]].push_back( Y[i] );
    }

    ys[0].clear();
    ys[n + 1].clear();
    for ( int x = 0; x <= n + 1; x++ )
        ys[x].push_back( 0 );
    for ( int x = 1; x <= n; x++ ) {
        sort( ys[x].begin(), ys[x].end() );
        ys[x].resize( unique( ys[x].begin(), ys[x].end() ) - ys[x].begin() );
    }

    for ( int x = 1; x <= n; x++ ) {
        vector<int> yss;
        for ( int i = 0; i < ys[x].size(); i++ )
            yss.push_back( ys[x][i] );
        for ( int i = 0; i < ys[x - 1].size(); i++ )
            yss.push_back( ys[x - 1][i] );
        for ( int i = 0; i < ys[x + 1].size(); i++ )
            yss.push_back( ys[x + 1][i] );
        sort( yss.begin(), yss.end() );
        yss.resize( unique( yss.begin(), yss.end() ) - yss.begin() );
        for ( int i = 1; i < yss.size(); i++ )
            spX[x][yss[i]] = spX[x][yss[i - 1]] + costCell[x][yss[i]];
    }

    dp[0][0] = dpLower[0][0] = 0;
    for ( int x = 1; x <= n + 1; x++ ) {
        for ( int i = 0; i < ys[x].size(); i++ ) {
            int crtY = ys[x][i];
            dp[x][crtY] = dpLower[x][crtY] = -INF;

            if ( x >= 1 ) {
                auto lower = upper_bound( ys[x - 1].begin(), ys[x - 1].end(), crtY );
                auto upper = lower_bound( ys[x - 1].begin(), ys[x - 1].end(), crtY );
                if ( lower != ys[x - 1].begin() ) {
                    lower--;
                    int prevY = *lower;
                    dpLower[x][crtY] = max( dpLower[x][crtY], maxPref1[x - 1][prevY] + spX[x - 1][crtY] );
                    dp[x][crtY] = max( dp[x][crtY], maxPref1[x - 1][prevY] + spX[x - 1][crtY] );
                }
                if ( upper != ys[x - 1].end() ) {
                    int prevY = *upper;
                    dp[x][crtY] = max( dp[x][crtY], maxSuf2[x - 1][prevY] - spX[x][crtY] );
                }
            }

            if ( x >= 2 ) {
                auto lower = upper_bound( ys[x - 2].begin(), ys[x - 2].end(), crtY );
                auto upper = lower_bound( ys[x - 2].begin(), ys[x - 2].end(), crtY );
                if ( lower != ys[x - 2].begin() ) {
                    lower--;
                    int prevY = *lower;
                    dpLower[x][crtY] = max( dpLower[x][crtY], maxPref3[x - 2][prevY] + spX[x - 1][crtY] );
                    dp[x][crtY] = max( dp[x][crtY], maxPref3[x - 2][prevY] + spX[x - 1][crtY] );
                }
                if ( upper != ys[x - 2].end() ) {
                    int prevY = *upper;
                    dpLower[x][crtY] = max( dpLower[x][crtY], maxSuf2[x - 2][prevY] );
                    dp[x][crtY] = max( dp[x][crtY], maxSuf2[x - 2][prevY] );
                }
            }

            maxPref1[x][crtY] = dpLower[x][crtY] - spX[x][crtY];
            maxSuf2[x][crtY] = dp[x][crtY] + spX[x + 1][crtY];
            maxPref3[x][crtY] = dpLower[x][crtY];
        }

        for ( int i = 1; i < ys[x].size(); i++ ) {
            maxPref1[x][ys[x][i]] = max( maxPref1[x][ys[x][i]], maxPref1[x][ys[x][i - 1]] );
            maxPref3[x][ys[x][i]] = max( maxPref3[x][ys[x][i]], maxPref3[x][ys[x][i - 1]] );
        }
        for ( int i = ys[x].size() - 2; i >= 0; i-- )
            maxSuf2[x][ys[x][i]] = max( maxSuf2[x][ys[x][i]], maxSuf2[x][ys[x][i + 1]] );
    }
    /*for ( int x = 0; x <= n + 1; x++ ) {
        for ( int i = 0; i < ys[x].size(); i++ )
            printf( "(%d %lld) ", ys[x][i], dp[x][i] );
        printf( "\n" );
    }*/

    return dp[n + 1][0];
}

Compilation message (stderr)

fish.cpp: In function 'long long int max_weights(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
fish.cpp:33:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |         for ( int i = 0; i < ys[x].size(); i++ )
      |                          ~~^~~~~~~~~~~~~~
fish.cpp:35:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |         for ( int i = 0; i < ys[x - 1].size(); i++ )
      |                          ~~^~~~~~~~~~~~~~~~~~
fish.cpp:37:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |         for ( int i = 0; i < ys[x + 1].size(); i++ )
      |                          ~~^~~~~~~~~~~~~~~~~~
fish.cpp:41:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |         for ( int i = 1; i < yss.size(); i++ )
      |                          ~~^~~~~~~~~~~~
fish.cpp:47:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |         for ( int i = 0; i < ys[x].size(); i++ ) {
      |                          ~~^~~~~~~~~~~~~~
fish.cpp:87:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   87 |         for ( int i = 1; i < ys[x].size(); i++ ) {
      |                          ~~^~~~~~~~~~~~~~

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