CSES - Datatähti 2021 loppu - Results
 Task: Järjestäminen Sender: intoo Submission time: 2021-01-23 19:02:18 +0200 Language: C++17 Status: READY Result: 0
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groupverdictscore
#10
#20
Test results
testverdicttimegroup
#10.01 s1, 2details
#20.02 s2details
#30.01 s1, 2details
#40.01 s1, 2details

### Code

```#include <iostream>
#include <vector>

using namespace std;

void swappair(vector<int>& v, vector<int>& d, int i, int j) {
swap(v[i+1], v[j+1]);
swap(d[v[i+1]], d[v[j+1]]);
swap(v[i], v[j]);
swap(d[v[i]], d[v[j]]);
}

int main() {
int t;
cin >> t;
while (t --> 0) {
int n;
cin >> n;
vector<int> v(n), d(n);
for (int i = 0; i < n; ++i) {
cin >> v[i];
d[--v[i]] = i;
}
bool b = 0;
for (int i = 0; i < n; ++i) {
if (d[i] == i) continue;
if ((d[i] == n-1 && i > n-4) || (n-d[i]-2 < 2 && d[i]-i < 2)) {
cout << "NO\n";
b = 1;
break;
} else if (d[i] == n-1) {
swappair(v, d, i+1, d[i]-1);
swappair(v, d, i, d[i]);
} else if (d[i]-i > 1) {
//cout << "else if: " << i << ' ' << d[i] << endl;
swappair(v, d, i, d[i]);
} else {
//cout << "else: " << i << ' ' << d[i] << endl;
swappair(v, d, d[i], d[i]+2);
swappair(v, d, i, d[i]);
}
}
if (b) continue;
cout << "YES\n";
}
}
```

### Test details

Group: 1, 2

Verdict:

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:

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

correct output
YES
NO
YES
NO
YES
...

user output
NO
NO
NO
NO
NO
...
Truncated

Group: 1, 2

Verdict:

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
NO
NO
NO
NO
YES
...
Truncated

Group: 1, 2

Verdict:

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
NO
NO
NO
...
Truncated