Submission #301450

#	Time	Username	Problem	Language	Result	Execution time	Memory
301450		easrui	Carnival Tickets (IOI20_tickets)	C++14	100 / 100	1037 ms	54512 KiB

tickets

#include "tickets.h"
#include <bits/stdc++.h>
#define va first
#define vb second
#define all(x) (x).begin(), (x).end()
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;

const int MN = 1505;

int D[MN],U[MN],f[MN][MN];

bool cmp(int x, int y)
{
    return D[x]<D[y];
}

ll find_maximum(int k, vector<vector<int>> x) {
    int n = x.size();
    int m = x[0].size();
    ll sum = 0;

    vector<vector<int>> ans;
    vector<int> row(m,-1);
    for(int i=0; i<n; i++){
        ans.push_back(row);
    }

    priority_queue<pii> PQ;
    for(int i=0; i<n; i++){
    	D[i] = k-1;
    	U[i] = m;
    	PQ.emplace(x[i][U[i]-1]+x[i][D[i]],i);
    }
    for(int i=0; i<n*k/2; i++){
    	int j = PQ.top().vb;
    	PQ.pop();
    	U[j]--;
    	D[j]--;
    	if(D[j]>=0) PQ.emplace(x[j][U[j]-1]+x[j][D[j]],j);
    }
    
    vector<int> v(n);
    for(int i=0; i<k; i++){
        for(int j=0; j<n; j++) v[j] = j;
        sort(all(v),cmp);
        for(int j=0; j<n; j++){
            if(j>=n/2){
                int c = v[j];
                ans[c][D[c]] = i;
                sum -= x[c][D[c]];
                D[c]--;
            }
            else{
                int c = v[j];
                ans[c][U[c]] = i;
                sum += x[c][U[c]];
                U[c]++;
            }
        }
    }
  
	allocate_tickets(ans);
    return sum;
}

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