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
#include <algorithm>
#include <cstdio>
#include <vector>

int main() {
    int n;
    scanf("%d", &n);
    std::vector<std::pair<int, int>> perm(n);
    for (int i = 0; i < n; ++i) {
        int a;
        scanf("%d", &a);
        perm[i] = {a, i};
    }
    std::sort(perm.begin(), perm.end());
    std::vector<std::vector<int>> cycles;
    bool one_turn = true;
    for (int i = 0; i < n; ++i) {
        if (perm[i].second != -1) {
            cycles.emplace_back();
            int current = i, next = perm[current].second;
            while (next != -1) {
                cycles.back().push_back(current);
                perm[current].second = -1;
                current = next;
                next = perm[current].second;
            }
            std::reverse(cycles.back().begin(), cycles.back().end());
            if (cycles.back().size() == 1) {
                cycles.pop_back();
            }
            else {
                one_turn &= cycles.back().size() % 2 == 0;
            }
        }
    }
    if (cycles.size() == 0) {
        printf("0\n");
        return 0;
    }
    if (one_turn) {
        printf("1\n");
        int total_size = 0;
        for (unsigned i = 0; i < cycles.size(); ++i) {
            total_size += cycles[i].size();
        }
        printf("%d\n", total_size);
        for (unsigned i = 0; i < cycles.size(); ++i) {
            for (unsigned j = 0; j < cycles[i].size() / 2; ++j) {
                printf("%d ", cycles[i][j] + 1);
            }
        }
        for (int i = cycles.size() - 1; i >= 0; --i) {
            for (unsigned j = cycles[i].size() / 2; j < cycles[i].size(); ++j) {
                printf("%d ", cycles[i][j] + 1);
            }
        }
        printf("\n");
    }
    else {
        printf("2\n");
        int total_size_1 = 0, total_size_2 = 0;
        for (unsigned i = 0; i < cycles.size(); ++i) {
            if (cycles[i].size() % 2 == 1) {
                total_size_1 += 2;
                total_size_2--;
            }
            total_size_2 += cycles[i].size();
        }
        printf("%d\n", total_size_1);
        for (unsigned i = 0; i < cycles.size(); ++i) {
            if (cycles[i].size() % 2 == 1) {
                printf("%d ", cycles[i][0] + 1);
            }
        }
        for (int i = cycles.size() - 1; i >= 0; --i) {
            if (cycles[i].size() % 2 == 1) {
                printf("%d ", cycles[i][1] + 1);
                auto it = cycles[i].begin();
                it++;
                cycles[i].erase(it);
            }
        }
        printf("\n%d\n", total_size_2);
        for (int i = cycles.size() - 1; i >= 0; --i) {
            for (unsigned j = 0; j < cycles[i].size() / 2; ++j) {
                printf("%d ", cycles[i][j] + 1);
            }
        }
        for (unsigned i = 0; i < cycles.size(); ++i) {
            for (unsigned j = cycles[i].size() / 2; j < cycles[i].size(); ++j) {
                printf("%d ", cycles[i][j] + 1);
            }
        }
        printf("\n");
    }
}