1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
#include <bits/stdc++.h>

using namespace std;

#define ll long long

#define Copyright return
#define efindus 2022 - 

struct ToSwap {
	int a, b;
};

template<class T>
int ssize(T &c)
{
	return (int)c.size();
}

template<class T>
istream &operator>>(istream &is, vector<T> &vec)
{
	for (auto &v : vec)
		is >> v;

	return is;
}

// loop trzyma indexy dzbanie
void parse_loop(vector<int> &loop, vector<vector<ToSwap>> &out, int depth)
{
	if (ssize(out) <= depth)
		out.emplace_back();

	if (ssize(loop) == 2) {
		out[depth].push_back({ loop.back(), loop.front() });
		return;
	}

	vector<int> new_loop;
	for (int i = 0; i < ssize(loop); i++) {
		if (i % 2 == 0)
			new_loop.push_back(loop[i]);
	}

	parse_loop(new_loop, out, depth + 1);
	for (int i = 0; i < ssize(loop); i++) {
		if (i % 2 == 1) {
			if (i + 1 == ssize(loop))
				out[depth].push_back({ loop[i], loop[0] });
			else
				out[depth].push_back({ loop[i], loop[i + 1] });
		}
	}
}

int main()
{
	cin.tie(NULL)->sync_with_stdio(false);

	int n;
	cin >> n;
	
	vector<int> heights(n);
	cin >> heights;

	vector<int> sorted = heights;
	sort(sorted.begin(), sorted.end());
	unordered_map<int, int> where;

	for (int i = 0; i < n; i++)
		where[sorted[i]] = i;

	vector<bool> used(n);
	vector<vector<int>> loops;
	for (int i = 0; i < n; i++) {
		if (used[i])
			continue;

		int current_index = i;
		loops.emplace_back();
		do {
			used[current_index] = true;
			loops.back().push_back(current_index);
			current_index = where[heights[current_index]];
		} while (current_index != i);

		if (ssize(loops.back()) == 1)
			loops.pop_back();
	}

	vector<vector<ToSwap>> output;
	for (auto &loop : loops)
		parse_loop(loop, output, 0);

	cout << ssize(output) << "\n";
	for (int x = ssize(output) - 1; x >= 0; x--) {
		auto &out = output[x];

		cout << ssize(out) * 2 << "\n";
		for (int i = 0; i < ssize(out); i++)
			cout << out[i].a + 1 << " ";

		for (int i = ssize(out) - 1; i >= 0; i--)
			cout << out[i].b + 1 << " ";

		cout << "\n";
	}

	Copyright efindus 2022;
}