// clang-format off #include <bits/stdc++.h> using namespace std; #define ALL(x) (x).begin(), (x).end() template<class C> void mini(C &a5, C b5) { a5 = min(a5, b5); } template<class C> void maxi(C &a5, C b5) { a5 = max(a5, b5); } #ifdef LOCAL const bool debug = true; #else const bool debug = false; #define cerr if (true) {} else cout #endif // clang-format on #define int long long #define double long double const int INF = 1e18; const int mod = 1e9 + 7; const int nax = 1e6 + 1000; int arr[nax]; bool visited[nax]; int n; vector<vector<pair<int, int> > > res; void dfs(int start) { int where = start; deque<int> q; do { visited[where] = true; q.push_back(where); where = arr[where]; } while (where != start); while (q.size() > 1) { res.back().push_back({q.front(), q.back()}); q.pop_front(); q.pop_back(); } } bool solve() { for (int i = 1; i <= n; i++) { visited[i] = false; } res.push_back({}); for (int i = 1; i <= n; i++) { if (!visited[i]) { dfs(i); } } if (res.back().empty()) { res.pop_back(); return false; } for (pair<int, int> i : res.back()) { swap(arr[i.first], arr[i.second]); } return true; } int32_t main() { ios_base::sync_with_stdio(0); cin.tie(0); cin >> n; vector<pair<int, int> > v; for (int i = 1; i <= n; i++) { int a; cin >> a; v.push_back({a, i}); } sort(ALL(v)); for (int i = 0; i < n; i++) { arr[v[i].second] = i+1; } for (int i = 1; i <= n; i++) { cerr << arr[i] << "\n"; } while (solve()) {} cout << res.size() << "\n"; for (auto &vv : res) { deque<int> d; for (pair<int, int> i : vv) { d.push_front(i.first); d.push_back(i.second); } cout << d.size() << "\n"; for (int i : d) { cout << i << " "; } cout << "\n"; } return 0; }/* 5 1670 2011 1560 1232 1447 * * 5 2 3 4 5 1 */
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 | // clang-format off #include <bits/stdc++.h> using namespace std; #define ALL(x) (x).begin(), (x).end() template<class C> void mini(C &a5, C b5) { a5 = min(a5, b5); } template<class C> void maxi(C &a5, C b5) { a5 = max(a5, b5); } #ifdef LOCAL const bool debug = true; #else const bool debug = false; #define cerr if (true) {} else cout #endif // clang-format on #define int long long #define double long double const int INF = 1e18; const int mod = 1e9 + 7; const int nax = 1e6 + 1000; int arr[nax]; bool visited[nax]; int n; vector<vector<pair<int, int> > > res; void dfs(int start) { int where = start; deque<int> q; do { visited[where] = true; q.push_back(where); where = arr[where]; } while (where != start); while (q.size() > 1) { res.back().push_back({q.front(), q.back()}); q.pop_front(); q.pop_back(); } } bool solve() { for (int i = 1; i <= n; i++) { visited[i] = false; } res.push_back({}); for (int i = 1; i <= n; i++) { if (!visited[i]) { dfs(i); } } if (res.back().empty()) { res.pop_back(); return false; } for (pair<int, int> i : res.back()) { swap(arr[i.first], arr[i.second]); } return true; } int32_t main() { ios_base::sync_with_stdio(0); cin.tie(0); cin >> n; vector<pair<int, int> > v; for (int i = 1; i <= n; i++) { int a; cin >> a; v.push_back({a, i}); } sort(ALL(v)); for (int i = 0; i < n; i++) { arr[v[i].second] = i+1; } for (int i = 1; i <= n; i++) { cerr << arr[i] << "\n"; } while (solve()) {} cout << res.size() << "\n"; for (auto &vv : res) { deque<int> d; for (pair<int, int> i : vv) { d.push_front(i.first); d.push_back(i.second); } cout << d.size() << "\n"; for (int i : d) { cout << i << " "; } cout << "\n"; } return 0; }/* 5 1670 2011 1560 1232 1447 * * 5 2 3 4 5 1 */ |