CSES - Datatähti 2021 loppu - Results
 Task: Järjestäminen Sender: hltk Submission time: 2021-01-23 17:44:59 +0200 Language: C++17 Status: READY Result: 100
Feedback
groupverdictscore
#1ACCEPTED36
#2ACCEPTED64
Test results
testverdicttimegroup
#1ACCEPTED0.01 s1, 2details
#2ACCEPTED0.01 s2details
#3ACCEPTED0.01 s1, 2details
#4ACCEPTED0.01 s1, 2details

### Code

```#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;

bool solve() {
int n;
cin >> n;

vector<int> a(n);
for (auto& x : a) cin >> x;

if (n == 4) return a == vector<int>{1, 2, 3, 4} || a == vector<int>{3, 4, 1, 2};
if (n < 4) return is_sorted(a.begin(), a.end());

bool ok = 1;
for (int i = 0; i < n; ++i) {
for (int j = i + 1; j < n; ++j) {
ok ^= a[i] > a[j];
}
}

return ok;
}

int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);

int t;
cin >> t;
for (int i = 0; i < t; ++i) cout << (solve() ? "YES" : "NO") << '\n';
}
```

### Test details

#### Test 1

Group: 1, 2

Verdict: ACCEPTED

input
153
1
1
2
1 2
...

correct output
YES
YES
NO
NO
NO
...

user output
YES
YES
NO
NO
NO
...
Truncated

#### Test 2

Group: 2

Verdict: ACCEPTED

input
1000
59
35 29 32 50 11 15 9 21 19 45 2...

correct output
YES
NO
YES
NO
YES
...

user output
YES
NO
YES
NO
YES
...
Truncated

#### Test 3

Group: 1, 2

Verdict: ACCEPTED

input
720
6
1 6 4 5 2 3
6
6 3 2 1 5 4
...

correct output
YES
NO
NO
NO
YES
...

user output
YES
NO
NO
NO
YES
...
Truncated

#### Test 4

Group: 1, 2

Verdict: ACCEPTED

input
1000
8
7 4 2 8 6 3 5 1
8
3 8 2 7 5 4 6 1
...

correct output
NO
NO
YES
NO
YES
...

user output
NO
NO
YES
NO
YES
...
Truncated