#include <bits/stdc++.h>
#define int long long
#define float double
#define pb push_back
#define F first
#define S second
#define T int t; cin >> t; while(t--)
#define IOS ios::sync_with_stdio(); cin.tie(0); cout.tie(0);
using namespace std;
const int inf = 8e18;
const int N = 1e6 + 6;
const int M = 1e3 + 3;
const int mod = 1e9 + 7;
const float pi = atan(1) * 4;
int a[N];
int n, m;
map<int, int> Pos;
vector<pair<int, int>> v;
main()
{
T
{
v.clear();
Pos.clear();
cin >> n;
for(int i = 1; i <= n ; i++)
cin >> a[i], Pos[a[i]] = i;
if (a[1] == n || a[n] == 1)
{
cout << "-1\n";
continue;
}
for(int i = 1; i <= n; i++)
{
if (a[i] == i)
continue;
int p = Pos[i];
swap(Pos[a[i]], Pos[a[p]]);
swap(a[i], a[p]);
v.pb({i, p});
swap(Pos[a[n - p + 1]], Pos[a[n - p + 1]]);
swap(a[n - i + 1], a[n - p + 1]);
}
cout << v.size() / 2 << ' ' << v.size() << '\n';
for(auto x: v)
cout << x.F << ' ' << x.S << '\n';
}
}
Compilation message
cat.cpp:22:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
22 | main()
| ^~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
15 ms |
384 KB |
Wrong answer |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
74 ms |
560 KB |
Wrong answer |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
15 ms |
384 KB |
Wrong answer |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
74 ms |
560 KB |
Wrong answer |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
15 ms |
384 KB |
Wrong answer |
2 |
Halted |
0 ms |
0 KB |
- |