Submission #838635

#	Time	Username	Problem	Language	Result	Execution time	Memory
838635		LucaIlie	Cake 3 (JOI19_cake3)	C++17	0 / 100	1 ms	212 KiB

cake3

#include <bits/stdc++.h>

using namespace std;

struct ab {
    int a, b;
};

int m;
const int MAX_N = 2e5;
const long long INF = 1e18;
ab v[MAX_N];
multiset<int> s;

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

    int l = (ll + lr) / 2;
    rl = max( rl, l + m );
    long long sumA = 0, answer = -INF;
    int bestR = rr;

    s.clear();
    for ( int r = l; r < rl; r++ ) {
        s.insert( v[r].a );
        sumA += v[r].a;
        if ( s.size() > m ) {
            sumA -= *s.begin();
            s.erase( s.begin() );
        }
    }

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

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

    return max( answer, max( solve( ll, l - 1, rl, bestR ), solve( l + 1, lr, bestR, rr ) ) );
}

int main() {
    int n;

    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:28:23: warning: comparison of integer expressions of different signedness: 'std::multiset<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   28 |         if ( s.size() > m ) {
      |              ~~~~~~~~~^~~
cake3.cpp:37:23: warning: comparison of integer expressions of different signedness: 'std::multiset<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   37 |         if ( s.size() > m ) {
      |              ~~~~~~~~~^~~
cake3.cpp:42:23: warning: comparison of integer expressions of different signedness: 'std::multiset<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   42 |         if ( s.size() >= m && r >= rl ) {
      |              ~~~~~~~~~^~~~

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