Submission #95037

#	Time	Username	Problem	Language	Result	Execution time	Memory
95037		Osama_Alkhodairy	DEL13 (info1cup18_del13)	C++17	6 / 100	11 ms	1008 KiB

del13

#include <bits/stdc++.h>
using namespace std;
#define finish(x) return cout << x << endl, 0
#define ll long long

void solve(){
    int n, k;
    cin >> n >> k;
    vector <int> a;
    for(int i = 0 ; i < k ; i++){
        int x;
        cin >> x;
        a.push_back(x);
    }
    a.push_back(0);
    a.push_back(n + 1);
    sort(a.begin(), a.end());
    vector <int> b;
    for(int i = 1 ; i < (int)a.size() ; i++)
        b.push_back(a[i] - a[i - 1] - 1);
    vector <int> c;
    for(auto &i : b){
        int x = i;
        int cur = 0;
        while(x >= 3){
            x -= 2;
            cur++;
        }
        c.push_back(cur);
    }
    for(int i = 0 ; i + 1 < (int)b.size() ; i++){
        while(b[i] >= 2 && c[i] && b[i + 1] < b[i])
            b[i] -= 2, c[i]--;
        if(b[i + 1] < b[i]){
            cout << -1 << endl;
            return;
        }
        b[i + 1] -= b[i];
    }
    if(b.back() % 2){
        cout << -1 << endl;
        return;
    }
    cout << 0 << endl << endl;
}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int T;
    cin >> T;
    while(T--) solve();
}

• Subtask 1: 0 / 15
• Subtask 2: 0 / 15
• Subtask 3: 6 / 15
• Subtask 4: 0 / 25
• Subtask 5: 0 / 30