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
#include <iostream>
#include <stdio.h>
#include <vector>
#include <algorithm>

using namespace std;

int n,res;
int a[3001],h[3001];
int v[3001];
vector<int> r[4],c;

void dfs(int i)
{
    v[i]=res;
    c.push_back(i);
    if(v[a[i]]<res) dfs(a[i]);
}

int main()
{
    scanf("%d",&n);
    //cout<<n<<endl;
    for(int i=1;i<=n;i++)
    {
        scanf("%d",&h[i]);
        //cout<<h[i]<<" ";
        h[i]=(h[i]<<15)+i;
    }
    //cout<<endl;
    sort(h+1,h+n+1);
    for(int i=1;i<=n;i++) a[h[i]&((1<<15)-1)]=i;


    while(true)
    {
        res++;
        for(int i=1;i<=n;i++)
        {
            if(v[i]<res&&a[i]!=i)
            {
                c.clear();
                dfs(i);
                for(int j=0;j*2<c.size()-1;j++)
                {
                    r[res].push_back(c[j]);
                    r[res].push_back(c[c.size()-j-1]);
                    swap(a[c[j]],a[c[c.size()-j-1]]);
                }
            }
        }

        if(r[res].size()==0) break;
    }

    printf("%d\n",res-1);
    for(int i=1;i<res;i++)
    {
        printf("%d\n",r[i].size());
        for(int j=0;j<r[i].size();j+=2) printf("%d ",r[i][j]);
        for(int j=r[i].size()-1;j>0;j-=2) printf("%d ",r[i][j]);
        printf("\n");
    }

    return 0;
}