Submission #494726

#	Time	Username	Problem	Language	Result	Execution time	Memory
494726		dannyboy20031204	DEL13 (info1cup18_del13)	C++17	15 / 100	59 ms	4416 KiB

del13

#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define mp make_pair 
using namespace std;
void db() {cout << endl;}
template <typename T, typename ...U> void db(T a, U ...b) {
    //return;
    cout << a << ' ', db(b...);
}
#ifdef Cloud
#define file freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout)
#else
#define file ios::sync_with_stdio(false); cin.tie(0)
#endif
const int N = 3001;
void solve(){
    int n, q;
    cin >> n >> q;
    bool stay[n + 1]{};
    for (int p, i = 0; i < q; i++) cin >> p, stay[p] = 1;
    set<pair<int, int>> s;
    vector<int> ans;
    for (int i = 1; i <= n; i++){
        if (!stay[i] and s.size() >= 2){
            auto u = *(--s.end());
            auto v = *(--(--s.end()));
            if (!u.se and !v.se){
                ans.push_back(u.fi);
                s.erase(u);
                s.erase(v);
            }
        }
        s.insert({i, stay[i]});
    }
    for (auto i : s){
        if (i.se == 0) continue;
        for (int t = 0; t < 2; t++){
            auto it = s.upper_bound(i);
            auto it2 = s.lower_bound(i);
            if (it == s.end() or it2 == s.begin()) continue;
            it2--;
            auto u = *it2, v = *it;
            if (u.se or v.se) continue;
            ans.push_back(i.fi);
            s.erase(u);
            s.erase(v);
        }
    }
    for (auto i : s){
        if (i.se == 0){
            cout << -1 << '\n';
            return;
        }
    }
    cout << ans.size() << '\n';
    for (int i : ans) cout << i << ' ';
    cout << '\n';
}
signed main(){
    file;
    int t;
    cin >> t;
    while (t--)
        solve();
}

• Subtask 1: 0 / 15
• Subtask 2: 0 / 15
• Subtask 3: 15 / 15
• Subtask 4: 0 / 25
• Subtask 5: 0 / 30