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
#include <bits/stdc++.h>
#include <queue>
using namespace std;

int n;
int t[3001];
int a[3001];
int b[3001];
bool visit2[3001];
vector<int> sol[3001];
void read() {
    cin>>n;
    for(int i =0;i<n;i++){
        cin>>t[i];
        a[i]=t[i];
    }
    sort(a,a+n);
    for(int i = 0;i<n;i++){
        b[a[i]]=i;
    }
    for(int i = 0;i<n;i++){
        t[i]=b[t[i]];
    }
    /*for(int i = 0;i<n;i++){
        cout<<t[i];
    }*/
}


int h[3001];
int h_size;
int k = 0;
void solve() {
    read();
    
    while(true){
        // mapuj
        for(int i =0;i<n;i++){
            a[t[i]]=i;
            visit2[i]=false;
        }
        h_size = 0;
        //cout<<"\n";
        for(int i = n-1;i>=0;i--){
            if(t[i]!=i && !visit2[i] && !visit2[a[i]]){
                h[h_size++]=i;
                h[h_size++]=a[i];
                visit2[i] = true;
                visit2[a[i]] = true;
               // cout<<i+1<<" "<<a[i]+1<<"\n";
            }
        }
        if(h_size==0)break;

        for(int i = 0; i < h_size;i+=2) {
            sol[k].push_back(h[i]);
            sol[k].push_back(h[i+1]);
            swap(t[h[i]],t[h[i+1]]);
        }
        k++;
    }
    cout<<k<<"\n";
    for(int i =0;i<k;i++){
        cout<<sol[i].size()<<"\n";
        for(int j=0;j<sol[i].size();j+=2)
            cout<<sol[i][j]+1<<" ";
        for(int j=sol[i].size()-1;j>=0;j-=2)
            cout<<sol[i][j]+1<<" ";
        cout<<"\n";
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    solve();
    return 0;
}