CSES - Datatähti Open 2021 - Results
Submission details
Task:Sorting
Sender:ScarletS
Submission time:2021-01-30 20:50:16 +0200
Language:C++ (C++17)
Status:READY
Result:0
Feedback
groupverdictscore
#10
#20
Test results
testverdicttimegroup
#10.01 s1, 2details
#20.01 s2details
#30.01 s1, 2details
#40.01 s1, 2details

Code

#include <bits/stdc++.h>
#define ll long long
#define sz(x) (int)(x).size()
using namespace std;
int n,a[101],b[101];
void swapper(int x, int y)
{
//cout<<x<<" "<<y<<"\n";
swap(a[x],a[y]);
swap(a[x+1],a[y+1]);
b[a[x]]=x;
b[a[y]]=y;
b[a[x+1]]=x+1;
b[a[y+1]]=y+1;
//for (int i=1;i<=n;++i)
// cout<<a[i]<<" ";
//cout<<"\n";
}
void solve()
{
cin>>n;
for (int i=1;i<=n;++i)
{
cin>>a[i];
b[a[i]]=i;
}
for (int i=1;i<=n;++i)
{
if (a[i]==i)
continue;
if (n-i+1<4)
{
cout<<"NO\n";
return;
}
if (b[i]==i+1)
{
if (n-i+1<=4)
{
cout<<"NO\n";
return;
}
swapper(i,i+2);
}
if (b[i]==n)
{
if (n-i+1<=4)
{
cout<<"NO\n";
return;
}
swapper(n-3,n-1);
}
else
swapper(i,b[i]);
}
cout<<"YES\n";
}
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0);
int n;
cin>>n;
while (n--)
solve();
return 0;
}

Test details

Test 1

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

Test 3

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
NO
...
Truncated

Test 4

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