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
#include <bits/stdc++.h>
using namespace std;
int n , l , w2 , x;
int tab[3005];
int tab2[3005];
int num[3005];
bool odw[3005];
vector<int> w[3005];
void czysc()
{
    for(int i = 1 ; i <= 3000 ; i ++)
        odw[i] = 0;
}
int main()
{
    ios_base::sync_with_stdio(0);   cin.tie(0);     cout.tie(0);
    cin >> n;
    for(int i = 1 ; i <= n ; i ++)
    {
        cin >> tab[i];
        tab2[i] = tab[i];
        num[tab[i]] = i;
    }
    sort(tab2 + 1 , tab2 + n + 1);
   while(1)
    {
        l = 0;
        for(int i = n ; i >= 1 ; i --)
        {
            if(tab[i] != tab2[i])
            {
                if(odw[i] == 0 && odw[num[tab2[i]]] == 0)
                {
                    //cout << i << " " << num[tab2[i]] << "\n";
                    x = num[tab2[i]];
                    odw[i] = 1;
                    odw[x] = 1;
                    w[w2].push_back(i); 
                    w[w2].push_back(x); 
                    swap(num[tab[i]] , num[tab[x]]);  
                    swap(tab[i] , tab[x]);  
                }
            }
            if(tab[i] == tab2[i])
                l ++;
        }
        czysc();
        if(l == n)
            break;
        w2 ++;
    }
if(w[0].size() != 0)
    cout << w2 + 1 << "\n";
for(int i = 0 ; i <= w2 ; i ++)
{
    cout << w[i].size() << "\n";
    for(int j = 0 ; j < w[i].size() ; j +=2)
        cout << w[i][j] << " ";
    for(int j = w[i].size() - 1 ; j >= 1 ; j -=2)
        cout << w[i][j] << " ";
    cout << "\n";   
}
    return 0;
}