Submission #430672

#	Time	Username	Problem	Language	Result	Execution time	Memory
430672		TryMax	Carnival Tickets (IOI20_tickets)	C++17	11 / 100	3 ms	716 KiB

tickets

#include "tickets.h"
#ifdef LOCAL
    #include "grader.cpp"
#endif // LOCAL
#include <bits/stdc++.h>

#define f first
#define s second
#define ll long long
#define pb push_back

using namespace std;

const int N = 2e6 + 10;

int have[N], was[N];

ll cost(vector<int> a){
    sort(a.begin(), a.end());
    int n = a.size();
    ll ans = 0;
    for(int i = 0; i < n / 2; ++i)
        ans += a[n / 2] - a[i];
    for(int i = n / 2; i < n; ++i)
        ans += a[i] - a[n / 2];
    return ans;
}

ll find_maximum(int k, vector<vector<int>> x){
    int n = x.size();
    int m = x[0].size();
    vector<pair<int, pair<int, int>>> a;
    for(int i = 0; i < n; ++i)
        for(int j = 0; j < m; ++j)
            a.pb({x[i][j], {i, j}});
    sort(a.begin(), a.end());
    vector<vector<int>> ans;
    ans.resize(n);
    for(int i = 0; i < n; ++i){
        ans[i].resize(m);
        for(int j = 0; j < m; ++j)
            ans[i][j] = -1;
    }
    int num = 0, l1 = 0, r1 = 0;
    ll ans1 = 0;
    vector<int> now;
    int l = 0, r = a.size() - 1;
    while(num < k){
        while(l < r && (have[a[l].s.f] || was[l]))
            ++l;
        while(l < r && (have[a[r].s.f] || was[r]))
            --r;
        if(a[l].s.f == a[r].s.f){
            if(a[l].f - l1 < r1 - a[r].f)
                --r;
            else
                ++l;
            continue;
        }
        ans[a[l].s.f][a[l].s.s] = num;
        now.pb(a[l].f);
        was[l] = 1;
        have[a[l].s.f] = 1;
        ans[a[r].s.f][a[r].s.s] = num;
        was[r] = 1;
        have[a[r].s.f] = 1;
        now.pb(a[r].f);
        if(now.size() == n){
            ans1 += cost(now);
            now.clear();
            for(int i = 0; i < n; ++i)
                have[i] = 0;
            ++num;
            l = -1, r = a.size();
        }
        ++l, --r;
    }
    allocate_tickets(ans);
    return ans1;
}
/*
2 3 2
0 2 5
1 1 3

7
0 -1 1
-1 1 0

4 2 1
5 9
1 4
3 6
2 7

12
-1 0
0 -1
0 -1
-1 0
*/

Compilation message (stderr)

tickets.cpp: In function 'long long int find_maximum(int, std::vector<std::vector<int> >)':
tickets.cpp:68:23: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   68 |         if(now.size() == n){
      |            ~~~~~~~~~~~^~~~

• 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