Submission #839001

#	Time	Username	Problem	Language	Result	Execution time	Memory
839001		LucaIlie	Cake 3 (JOI19_cake3)	C++17	24 / 100	4035 ms	16584 KiB

cake3

#include <bits/stdc++.h>

using namespace std;

struct ab {
    int a, b;
};

struct event {
    int type, val, t;
};

int m;
const int MAX_N = 2e5;
const long long INF = 1e18;
ab v[MAX_N + 1];
int timee = 0;
long long sumA;
vector<event> events;

multiset<int> s;

void rollback( int t ) {
    while ( !events.empty() && events.back().t > t ) {
        int x = events.back().val;
        if (events.back().type == 1 ) {
            s.erase( s.find( x ) );
            sumA -= x;
        } else {
            s.insert( x );
            sumA += x;
        }
        events.pop_back();
    }
}

long long solve( int ll, int lr, int rl, int rr ) {
    if ( ll > lr || rl > rr )
        return -INF;


    int l = (ll + lr) / 2;
    long long answer = -INF;
    int bestR = rr;
    int t = timee;

    for ( int i = l; i <= lr && i < rl; i++ ) {
        sumA += v[i].a;
        events.push_back( { 1, v[i].a, ++timee, } );
        s.insert( v[i].a );
        if ( s.size() > m ) {
            sumA -= *s.begin();
            events.push_back( { -1, *s.begin(), ++timee, } );
            s.erase( s.begin() );
        }
    }

    for ( int r = max( l, rl ); r <= rr; r++ ) {
        s.insert( v[r].a );
        sumA += v[r].a;
        events.push_back( { 1, v[r].a, ++timee, } );
        if ( s.size() > m ) {
            sumA -= *s.begin();
            events.push_back( { -1, *s.begin(), ++timee, } );
            s.erase( s.begin() );
        }

        if ( s.size() >= m ) {
            if ( sumA - 2 * (v[r].b - v[l].b) > answer ) {
                answer = sumA - 2 * (v[r].b - v[l].b);
                bestR = r;
            }
        }
    }


    if ( ll <= l - 1 ) {
        rollback( t );
        for ( int i = min( rl - 1, lr ); i >= l; i-- ) {
            s.insert( v[i].a );
            sumA += v[i].a;
            events.push_back( { 1, v[i].a, ++timee, } );
            if ( s.size() > m ) {
                sumA -= *s.begin();
                events.push_back( { -1, *s.begin(), ++timee, } );
                s.erase( s.begin() );
            }
        }
        answer = max( answer, solve( ll, l - 1, rl, bestR ) );
    }


    if ( l + 1 <= lr ) {
        rollback( t );
        for ( int i = max( rl, lr + 1 ); i < bestR; i++ ) {
            s.insert( v[i].a );
            sumA += v[i].a;
            events.push_back( { 1, v[i].a, ++timee, } );
            if ( s.size() > m ) {
                sumA -= *s.begin();
                events.push_back( { -1, *s.begin(), ++timee, } );
                s.erase( s.begin() );
            }
        }
        answer = max( answer, solve( l + 1, lr, bestR, rr ) );
    }

    rollback( t );
    return answer;
}

int main() {
    int n;

    cin.tie( NULL );
    ios_base::sync_with_stdio( false );

    cin >> n >> m;
    for ( int i = 1; i <= n; i++ )
        cin >> v[i].a >> v[i].b;
    sort( v + 1, v + 1 + n, []( ab x, ab y ) {
        return x.b < y.b;
    } );

    cout << solve( 1, n, 1, n );

    return 0;
}

Compilation message (stderr)

cake3.cpp: In function 'long long int solve(int, int, int, int)':
cake3.cpp:51:23: warning: comparison of integer expressions of different signedness: 'std::multiset<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   51 |         if ( s.size() > m ) {
      |              ~~~~~~~~~^~~
cake3.cpp:62:23: warning: comparison of integer expressions of different signedness: 'std::multiset<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   62 |         if ( s.size() > m ) {
      |              ~~~~~~~~~^~~
cake3.cpp:68:23: warning: comparison of integer expressions of different signedness: 'std::multiset<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   68 |         if ( s.size() >= m ) {
      |              ~~~~~~~~~^~~~
cake3.cpp:83:27: warning: comparison of integer expressions of different signedness: 'std::multiset<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   83 |             if ( s.size() > m ) {
      |                  ~~~~~~~~~^~~
cake3.cpp:99:27: warning: comparison of integer expressions of different signedness: 'std::multiset<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   99 |             if ( s.size() > m ) {
      |                  ~~~~~~~~~^~~

• Subtask 1: 5 / 5
• Subtask 2: 19 / 19
• Subtask 3: 0 / 76