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
#include<bits/stdc++.h>
using namespace std;
pair<int,int>leg[3010];
int tab[3010];
vector<vector<pair<int,int>>>pary;
bool zaz[3010];
int main()
{
	int n, i;
	scanf("%d", &n);
	for(i=1;i<=n;i++){
		scanf("%d", &leg[i].first);
		leg[i].second = i;
	}
	sort(leg+1, leg+n+1);
	for(i=1;i<=n;i++){
		tab[leg[i].second] = i;
	}
	while(1){
		bool czy = 0;
		for(i=1;i<=n;i++){
			if(tab[i]!=i){
				czy = 1;
				break;
			}
		}
		//printf("#\n");
		if(czy==0)
			break;
		pary.push_back({});
		for(i=1;i<=n;i++)zaz[i] = 0;
		
		for(i=1;i<=n;i++){
			if(tab[i]==i || zaz[i]==1)
				continue;
			vector<int>perm;
			perm.push_back(i);
			zaz[i] = 1;
			int j  = i;
			while(tab[j]!=perm[0]){
				j = tab[j];
				zaz[j] = 1;
				perm.push_back(j);
			}
			if(perm.size()==2){
				pary.back().push_back({perm[0], perm[1]});
				continue;
			}
			for(j=1;j<(int)perm.size();j++){
				if(j>=(int)perm.size()-j)
					break;
				pary.back().push_back({perm[j], perm[perm.size()-j]});
			}
		}
		for(auto j: pary.back()){
			swap(tab[j.first], tab[j.second]);
		}
	}
	printf("%d\n", (int)pary.size());
	for(auto j: pary){
		printf("%d\n", 2*j.size());
		for(i=0;i<(int)j.size();i++){
			printf("%d ", j[i].first);
		}
		for(i=j.size()-1;i>=0;i--){
			printf("%d ", j[i].second);
		}
		printf("\n");
	}
}