Submission #486853

#	Time	Username	Problem	Language	Result	Execution time	Memory
486853		couplefire	Table Tennis (info1cup20_tabletennis)	C++17	100 / 100	345 ms	33044 KiB

tabletennis

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

int n, k, m, arr[200405];

void check(int sum){
    vector<int> res;
    for(int l = 0, r = m-1; l<r;){
        if(arr[l]+arr[r]==sum) res.push_back(arr[l]), res.push_back(arr[r]), ++l, --r;
        else if(arr[l]+arr[r]<sum) ++l;
        else --r;
    }
    while((int)res.size()>n) res.pop_back();
    if((int)res.size()<n) return;
    sort(res.begin(), res.end());
    for(auto x : res)
        cout << x << ' ';
    cout << '\n'; exit(0);
}

int main(){
    // freopen("a.in", "r", stdin);
    cin.tie(0)->sync_with_stdio(0);
    cin >> n >> k; m = n+k;
    for(int i = 0; i<m; ++i)
        cin >> arr[i];
    sort(arr, arr+m);
    vector<int> todo;
    if(m<4*k){
        for(int i = 0; i<m; ++i)
            for(int j = i+1; j<m; ++j)
                todo.push_back(arr[i]+arr[j]);
        sort(todo.begin(), todo.end());
        todo.erase(unique(todo.begin(), todo.end()), todo.end());
    } else{
        map<int, int> cnt;
        for(int i = 0; i<2*k; ++i)
            for(int j = 0; j<2*k; ++j)
                cnt[arr[i]+arr[m-1-j]]++;
        for(auto [x, y] : cnt)
            if(y>=k) todo.push_back(x);
    }
    for(auto x : todo)
        check(x);
}

• Subtask 1: 11 / 11
• Subtask 2: 9 / 9
• Subtask 3: 14 / 14
• Subtask 4: 15 / 15
• Subtask 5: 9 / 9
• Subtask 6: 14 / 14
• Subtask 7: 15 / 15
• Subtask 8: 13 / 13