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
#include<bits/stdc++.h>
 
#define pb push_back
#define fi first
#define se second
#define turbo ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define vll vector<pll>
#define vii vector<pii>
#define vi vector<int>
#define vl vector<ll>
#define vvi vector<vi>
#define vvii vector<vii>
#define vc vector<char>
#define vvc vector<vector<char>>
#define vb vector<bool>
#define vvb vector<vb>
#define mid (l+r)/2
#define endl '\n'
#define lowbit(x) x&(-x)
#define bits(x) __builtin_popcount(x) 
#define mins(se) (*se.begin())
#define maxs(se) (*--se.end())
#define ALL(x) x.begin(), x.end()

using namespace std;

vvii res;
vi v;
vb vis;

void cyklTescia(int e, vi& sto) {
    if(vis[e])
        return;
    vis[e] = true;
    sto.pb(e);
    cyklTescia(v[e], sto);
}

int main() {
    turbo
    int n; cin >> n;
    vii prz(n);
    v = vi(n);

    for(int i = 0; i < n; i++) {
        cin >> prz[i].fi;
        prz[i].se = i;
    }
    sort(ALL(prz));
    for(int i = 0; i < n; i++)
        v[prz[i].se] = i;

    while(true) {
        vis = vb(n);
        vvi cykle;
        vii pom;

        for(int i = 0; i < n; i++)
            if(!vis[i] and v[i] != i) {
                vi sto;
                cyklTescia(i, sto);
                cykle.pb(move(sto));
            }
        for(auto &ck : cykle) {
            if(ck.size() == 2) {
                pom.pb({ck[0]+1, ck[1]+1});
                swap(v[ck[0]], v[ck[1]]);
                continue;
            }
            int i = 1, j = ck.size()-1;
            while(i < j) {
                pom.pb({ck[i]+1, ck[j]+1});
                swap(v[ck[i]], v[ck[j]]);
                i++; j--;
            }
        }
        
        if(pom.empty())
            break;
        res.pb(move(pom));
    }

    cout << res.size() << "\n";
    for(auto &ve : res) {
        cout << ve.size()*2 << "\n";
        for(auto &it : ve)
            cout << it.fi << " ";
        for(int i = ve.size()-1; i >= 0; i--)
            cout << ve[i].se << " ";
        cout << "\n";
    }
}