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
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
#include <bits/stdc++.h>

using namespace std;

vector <pair<int, int>> start;
vector <pair<int, int>> ending;
bitset<3007> used;
bitset<3007> git;
deque <int> q;
vector <vector<int>> ciag[30000];
vector <deque<int>> odp;
int n, h, x = 1, y, maxi, done; 

void findCycles(){ 
     used.reset();
     x = 1;
     maxi = 0;
     while(x <= n){
        vector<int> temp;
        if(!git[ending[x-1].first] && !used[ending[x-1].first]){
            used[ending[x-1].first] = true;
            temp.push_back(ending[x-1].first);
            y = ending[x-1].second;
            while(!used[ending[y-1].first]){
                used[ending[y-1].first] = true;
                temp.push_back(ending[y-1].first);
                y = ending[y-1].second;
            }
            ciag[temp.size()].push_back(temp);
            if(temp.size() > maxi)
                maxi = temp.size();
        }
        x++;
    }
}

void check(){
    done = 0;
    for(int i = 0; i < n; i++){
        if(ending[i].first == ending[i].second){
            git[ending[i].second] = true;
            done++;
        }
    }
}

void wypisz(){
    for(int i = 0; i < n; i++){
        cout << ending[i].first << " ";
    }
    cout << endl;
    for(int i = 0; i < n; i++){
        cout << ending[i].second << " ";
    }
    cout << endl;
}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    cin >> n;
    
    for(int i = 0; i < n; i++){
        cin >> h;
        start.push_back({h, i+1});
    }

    sort(start.begin(), start.end());

    for(int i = 0; i < n; i++){
        ending.push_back({start[i].second, i+1});
    }
    sort(ending.begin(), ending.end());
    //oznacz te które są na swoich miejsach 
    check();
    // wypisz();
    // return 0;
    // cout << endl << endl;
    
    //chyba lepsza wersja findcycles?
    while(done != n){
        used.reset();
        x = 1;
        maxi = 0;
        while(x <= n){
            if(!git[ending[x-1].second] && !git[ending[x-1].first] && !used[ending[x-1].first] && !used[ending[x-1].second]){
                used[ending[x-1].first] = true;
                used[ending[x-1].second] = true;
                q.push_front(ending[x-1].first);
                q.push_back(ending[x-1].second);
                // cout << q.front() << " " 
                swap(ending[q.front()-1].second, ending[q.back()-1].second);
            }
            x++;
        }
        if(q.size() != 0)
            odp.push_back(q);
        q.clear();
        check();

    }
    
    
    
    
    // while(done != n){
    //     findCycles();
    //     for(int i = 2; i <= maxi; i++){
    //         if(ciag[i].size() != 0){
    //             for(auto e : ciag[i]){
    //                 for(int k = 0; k < e.size()/2; k++){
    //                     q.push_front(e[2*k]);
    //                     q.push_back(e[2*k + 1]);
    //                 }
    //             }
    //         }
    //     }   
    //     odp.push_back(q);

    //     for(auto e : q){
    //         cout << e << " ";
    //     }
    //     cout << endl;
    //     while(!q.empty()){
    //         swap(ending[q.front()-1].second, ending[q.back()-1].second);
    //         q.pop_back();
    //         q.pop_front();
    //     }
    //     check();
    //     wypisz();
    //     cout << endl;
    // }
    
    cout << odp.size() << endl;
    for(int i = 0; i < odp.size(); i++){
        cout << odp[i].size() << endl;
        for(int j = 0; j < odp[i].size(); j++){
            cout << odp[i][j] << " ";
        }
        cout << endl;
    }
    return 0;
}