#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);
for(int i = 0 ; i + 1 < (int)b.size() ; i++)
b[i + 1] -= b[i], b[i] = 0;
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();
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
376 KB |
Output isn't correct |
2 |
Incorrect |
3 ms |
376 KB |
Output isn't correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
376 KB |
Output isn't correct |
2 |
Incorrect |
3 ms |
376 KB |
Output isn't correct |
3 |
Incorrect |
11 ms |
376 KB |
Output isn't correct |
4 |
Incorrect |
10 ms |
376 KB |
Output isn't correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
4 ms |
376 KB |
Output isn't correct |
2 |
Incorrect |
3 ms |
376 KB |
Output isn't correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
376 KB |
Output isn't correct |
2 |
Incorrect |
3 ms |
376 KB |
Output isn't correct |
3 |
Incorrect |
11 ms |
376 KB |
Output isn't correct |
4 |
Incorrect |
10 ms |
376 KB |
Output isn't correct |
5 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
6 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
7 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
376 KB |
Output isn't correct |
2 |
Incorrect |
3 ms |
376 KB |
Output isn't correct |
3 |
Incorrect |
11 ms |
376 KB |
Output isn't correct |
4 |
Incorrect |
10 ms |
376 KB |
Output isn't correct |
5 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
6 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
7 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
8 |
Incorrect |
7 ms |
376 KB |
Output isn't correct |
9 |
Incorrect |
8 ms |
620 KB |
Output isn't correct |
10 |
Incorrect |
7 ms |
664 KB |
Output isn't correct |
11 |
Incorrect |
7 ms |
888 KB |
Output isn't correct |