oj.uz

Submission #924650

# Submission time Handle Problem Language Result Execution time Memory
924650 2024-02-09T11:18:26 Z Ianis Cat (info1cup19_cat) C++17
25 / 100
 314 ms 32288 KB 
#ifdef LOCAL
#include <iostream>
#include <fstream>
#include <iomanip>
#include <cassert>
#include <random>
#include <vector>
#include <queue>
#include <stack>
#include <set>
#include <map>
#else
#pragma GCC optimize("Ofast,unroll-loops")
#include <bits/stdc++.h>
#define cerr if (false) cerr 
#define endl '\n'
#endif

#define fi first
#define se second

#define sz(a) ((int)(a).size())
#define all(a) (a).begin(), (a).end()

#define lsb(x) (x & (-x))

#define bit(mask, i) (((mask) >> (i)) & 1)
#define popcount(x) __builtin_popcount(x)

#define YES cout << "YES" << endl
#define NO cout << "NO" << endl

using namespace std;

template <typename T>
bool ckmax(T &a, T b) { return a < b ? a = b, true : false; }
template <typename T>
bool ckmin(T &a, T b) { return a > b ? a = b, true : false; }

using ll = long long;
using pii = pair<int, int>;

const int NMAX = 3e6+5;

int n;
int a[NMAX];
int pos[NMAX];
vector<pii> ans;

void read() {
   cin >> n;
   for (int i = 1; i <= n; i++) {
      cin >> a[i];
      pos[a[i]] = i;
   }
}

void my_swap(int i, int j) {
   ans.push_back({ i, j });
   swap(pos[a[i]], pos[a[j]]);
   swap(a[i], a[j]);
   swap(pos[a[n - i + 1]], pos[a[n - j + 1]]);
   swap(a[n - i + 1], a[n - j + 1]);
}

void solve() {
   ans.clear();
   for (int i = 1; i <= n / 2; i++) {
      if (a[i] != i)
         my_swap(i, pos[i]);
   }
   for (int i = 1; i <= n; i++) {
      if (a[i] != i) {
         cout << -1 << endl;
         return;
      }
   }
   cout << ans.size() << ' ' << ans.size() << endl;
   for (auto &[ i, j ] : ans)
      cout << i << ' ' << j << endl;
}

signed main() {
#ifdef LOCAL
   freopen("input.txt", "r", stdin);
#endif
   ios_base::sync_with_stdio(false);
   cin.tie(0);
   cout.tie(0);
   
   int t = 1;
   cin >> t;

   while (t--) {
      read();
      solve();
   }

   return 0;
}

Subtask #1
0.0 / 15.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 2392 KB Wrong answer
2 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 3160 KB Output is correct
2 Correct 13 ms 3164 KB Output is correct

Subtask #3
0.0 / 25.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 2392 KB Wrong answer
2 Halted 0 ms 0 KB -

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 3160 KB Output is correct
2 Correct 13 ms 3164 KB Output is correct
3 Correct 298 ms 31692 KB Output is correct
4 Correct 284 ms 30404 KB Output is correct
5 Correct 314 ms 32288 KB Output is correct

Subtask #5
0.0 / 35.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 2392 KB Wrong answer
2 Halted 0 ms 0 KB -