Submission #168805

#	Time	Username	Problem	Language	Result	Execution time	Memory
168805		Akashi	Cake 3 (JOI19_cake3)	C++14	24 / 100	4035 ms	13636 KiB

cake3

#include <bits/stdc++.h>
using namespace std;

const long long INF = 1e18;

struct cake{
    int v, c;
    bool operator < (const cake &aux)const{
        if(c != aux.c) return c < aux.c;
        return v > aux.v;
    }
};
cake a[200005];

int n, m;

set <pair <long long, int> > s1, s2;
long long S = 0;
void add(int i){
    if(s2.size() < m){
        s2.insert({a[i].v, i});
        S += a[i].v;
    }
    else{
        if(s2.begin()->first < a[i].v){
            s1.insert({s2.begin()->first, s2.begin()->second});
            S -= s2.begin()->first;

            s2.erase(s2.begin());
            s2.insert({a[i].v, i});
            S += a[i].v;
        }
        else s1.insert({a[i].v, i});
    }
}

void rem(int i){
    if(s2.find({a[i].v, i}) != s2.end()){
        s2.erase({a[i].v, i});
        S -= a[i].v;
        if(!s1.empty()){
            s2.insert({s1.rbegin()->first, s1.rbegin()->second});
            S += s1.rbegin()->first;
            s1.erase({s1.rbegin()->first, s1.rbegin()->second});
        }
    }
    else s1.erase({a[i].v, i});
}

int l = 1, r = 0;
long long calc(int st, int dr){
    while(r < dr) add(++r);
    while(l > st) add(--l);
    while(l < st) rem(l++);
    while(r > dr) rem(r--);

    if(dr - st + 1 < m) return -INF;
    return S;
}

long long ans = -INF;
void solve(int st, int dr, int down, int up){
    int mij = (st + dr) / 2;

    long long sol = -INF, best = 0;
    for(int i = max(down, mij); i <= up ; ++i){
        long long val = calc(mij, i) - (a[i].c - a[mij].c);
        if(val > sol){
            sol = val;
            best = i;
        }
    }

    ans = max(ans, sol);
    if(st == dr) return ;

    solve(mij + 1, dr, best, up);
    solve(st, mij, down, best);
}

int main()
{
    scanf("%d%d", &n, &m);

    for(int i = 1; i <= n ; ++i){
        scanf("%d%d", &a[i].v, &a[i].c);
        a[i].c *= 2;
    }

    sort(a + 1, a + n + 1);

    solve(1, n - m + 1, m, n);
    printf("%lld", ans);

    return 0;
}

Compilation message (stderr)

cake3.cpp: In function 'void add(int)':
cake3.cpp:20:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if(s2.size() < m){
        ~~~~~~~~~~^~~
cake3.cpp: In function 'int main()':
cake3.cpp:83:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &n, &m);
     ~~~~~^~~~~~~~~~~~~~~~
cake3.cpp:86:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &a[i].v, &a[i].c);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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