Submission #603978

#	Time	Username	Problem	Language	Result	Execution time	Memory
603978		lcj	Carnival Tickets (IOI20_tickets)	C++17	11 / 100	2 ms	724 KiB

tickets

#include <bits/stdc++.h>
#define fi first
#define se second
using namespace std;

typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;

#include "tickets.h"



ll find_maximum(int k, vector<vector<int>> x) {
	int n = x.size();
	int m = x[0].size();
    vector<int> lidx(n, 0), hidx(n, m-1);
    
    ll su = 0;
    vector<vector<int>> ans(n, vector<int>(m, -1));
    for (int cur = 0; cur < k; cur++)
    {
        multiset<pii> active;
        for (int i = 0; i < n; i++)
        {
            active.insert({x[i][lidx[i]], i});
            if (lidx[i] != hidx[i]) {
                active.insert({x[i][hidx[i]], i});
            }
        }
        for (int i = 0; i < n/2; i++)
        {
            auto lo = active.begin();auto hi = --active.end();
            multiset<pii>::iterator c1, c2;
            c1 = lo;c2 = hi;
            if (lo->se != hi->se) {
                c1 = lo;c2 = hi;
            }
            else {
                auto c11 = c1;
                auto c22 = c2;
                ++c1;
                --c2;
                if (c2->se - c11->se > c22->se - c1->se) {
                    c1 = c11;
                }
                else {
                    c2 = c22;
                }
            }
            su += c2->fi-c1->fi;
            ans[c1->se][lidx[c1->se]] = cur;
            ans[c2->se][hidx[c2->se]] = cur;
            int col1 = c1->se;
            int col2 = c2->se;
            active.erase(c1);
            active.erase(c2);
            if (lidx[col1] != hidx[col1]) {
                active.erase(active.find({x[col1][hidx[col1]], col1}));
            }
            if (lidx[col2] != hidx[col2]) {
                active.erase(active.find({x[col2][lidx[col2]], col2}));
            }
            lidx[col1]++;
            hidx[col2]--;
        }        
    }
	allocate_tickets(ans);
	return su;
}

• Subtask 1: 11 / 11
• Subtask 2: 0 / 16
• Subtask 3: 0 / 14
• Subtask 4: 0 / 14
• Subtask 5: 0 / 12
• Subtask 6: 0 / 23
• Subtask 7: 0 / 10