#include <bits/stdc++.h> //#pragma GCC optimize("Ofast") //#pragma GCC optimize ("unroll-loops") //#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native") //Jakub Misiaszek //szablon czesciowo skopiowany z profilu https://codeforces.com/profile/Geothermal using namespace std; typedef long long LL; typedef long double LD; typedef pair<int, int> pii; typedef pair<LL,LL> pll; typedef pair<LD,LD> pdd; typedef vector<int> vi; typedef vector<bool> vb; typedef vector<LD> vld; typedef vector<LL> vll; typedef vector<pii> vpii; typedef vector<pll> vpll; template<class T> using pq = priority_queue<T>; template<class T> using pqg = priority_queue<T, vector<T>, greater<T>>; #define rep(i, a, b) for (int i=a; i<(b); i++) #define repd(i,a,b) for (int i = (a); i >= b; i--) #define sz(x) (int)(x).size() #define pb push_back #define st first #define nd second #define lb lower_bound #define ub upper_bound #define all(x) x.begin(), x.end() #define memo(x) memset(x, 0, sizeof(x)) #define debug(x) cerr << x << " " mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); LL losuj(LL a, LL b){ return a+rng()%(b-a+1);} void solve(){ int n; cin >> n; vpii t(n); for(int i = 0; i < n; i++){ int x; cin >> x; t[i] = {x, i+1}; } sort(all(t)); vi g(n+1,0), rev(n+1, 0); for(int i = 0; i < n; i++){ g[t[i].nd] = i + 1; rev[i + 1] = t[i].nd; } vi vis(n+1, -1); vpii ans[2]; int it = 0; for(int i = 1; i <= n; i++){ if(rev[i] != g[i]){ int k = i; while(rev[k] != g[k]){ int tmp = rev[k]; ans[0].pb({g[k], rev[k]}); g[rev[k]] = g[g[k]]; rev[g[g[k]]] = rev[k]; rev[k] = g[k]; g[g[k]] = k; k = tmp; } } } for(int i = 1; i <= n; i++){ if(g[i] != i){ ans[1].pb({i,g[i]}); g[g[i]] = g[i]; g[i] = i; } } cout << (sz(ans[0]) > 0) + (sz(ans[1]) > 0) << "\n"; for(auto x:ans){ if(sz(x) > 0){ cout << sz(x) * 2 << "\n"; for(int i = 0; i < sz(x); i++) cout << x[i].st << " "; for(int i = sz(x) - 1; i >= 0; i--) cout << x[i].nd << " "; cout << "\n"; } } } int main(){ ios_base::sync_with_stdio(0); cin.tie(0); int t = 1; //cin >> t; while (t--) solve(); return 0; }
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 | #include <bits/stdc++.h> //#pragma GCC optimize("Ofast") //#pragma GCC optimize ("unroll-loops") //#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native") //Jakub Misiaszek //szablon czesciowo skopiowany z profilu https://codeforces.com/profile/Geothermal using namespace std; typedef long long LL; typedef long double LD; typedef pair<int, int> pii; typedef pair<LL,LL> pll; typedef pair<LD,LD> pdd; typedef vector<int> vi; typedef vector<bool> vb; typedef vector<LD> vld; typedef vector<LL> vll; typedef vector<pii> vpii; typedef vector<pll> vpll; template<class T> using pq = priority_queue<T>; template<class T> using pqg = priority_queue<T, vector<T>, greater<T>>; #define rep(i, a, b) for (int i=a; i<(b); i++) #define repd(i,a,b) for (int i = (a); i >= b; i--) #define sz(x) (int)(x).size() #define pb push_back #define st first #define nd second #define lb lower_bound #define ub upper_bound #define all(x) x.begin(), x.end() #define memo(x) memset(x, 0, sizeof(x)) #define debug(x) cerr << x << " " mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); LL losuj(LL a, LL b){ return a+rng()%(b-a+1);} void solve(){ int n; cin >> n; vpii t(n); for(int i = 0; i < n; i++){ int x; cin >> x; t[i] = {x, i+1}; } sort(all(t)); vi g(n+1,0), rev(n+1, 0); for(int i = 0; i < n; i++){ g[t[i].nd] = i + 1; rev[i + 1] = t[i].nd; } vi vis(n+1, -1); vpii ans[2]; int it = 0; for(int i = 1; i <= n; i++){ if(rev[i] != g[i]){ int k = i; while(rev[k] != g[k]){ int tmp = rev[k]; ans[0].pb({g[k], rev[k]}); g[rev[k]] = g[g[k]]; rev[g[g[k]]] = rev[k]; rev[k] = g[k]; g[g[k]] = k; k = tmp; } } } for(int i = 1; i <= n; i++){ if(g[i] != i){ ans[1].pb({i,g[i]}); g[g[i]] = g[i]; g[i] = i; } } cout << (sz(ans[0]) > 0) + (sz(ans[1]) > 0) << "\n"; for(auto x:ans){ if(sz(x) > 0){ cout << sz(x) * 2 << "\n"; for(int i = 0; i < sz(x); i++) cout << x[i].st << " "; for(int i = sz(x) - 1; i >= 0; i--) cout << x[i].nd << " "; cout << "\n"; } } } int main(){ ios_base::sync_with_stdio(0); cin.tie(0); int t = 1; //cin >> t; while (t--) solve(); return 0; } |