Submission #1160172

#TimeUsernameProblemLanguageResultExecution timeMemory
1160172countlessVillage (BOI20_village)C++20
100 / 100
88 ms26308 KiB
#include <bits/stdc++.h> using namespace std; typedef long long ll; typedef long double ld; typedef vector<int> vi; typedef vector<vector<int>> vvi; typedef vector<long long> vll; typedef vector<vector<long long>> vvll; typedef pair<int, int> pii; typedef pair<long long, long long> pll; typedef set<int> si; typedef set<long long> sll; const ll MOD = 998244353; const ld EPS = 1e-12; #define endl "\n" #define sp <<" "<< #define forn(i, n) for(ll i = 0; i < n; i++) #define rforn(i, n) for(ll i = n; i >= 0; i--) #define dbg(x) cout << #x << " = " << x << endl #define mp make_pair #define pb push_back #define fi first #define se second #define INF 1e18 #define fast_io() ios_base::sync_with_stdio(false); cin.tie(NULL) #define all(x) (x).begin(), (x).end() #define rall(x) (x).rbegin(), (x).rend() #define sz(x) ((ll)(x).size()) int N; ll mn = 0, mx = 0; vector<int> ansMin, ansMax, depth, subtSz; unordered_map<int, set<int>> subt; int getSubtrSz(int node, vector<vector<int>> &adj, int parent = -1) { int &res = subtSz[node]; res = 1; for (int i : adj[node]) { if (i == parent) { continue; } res += getSubtrSz(i, adj, node); } return res; } int getCentroid(int node, vector<vector<int>> &adj, int parent = -1) { for (int i : adj[node]) { if (i == parent) { continue; } if (subtSz[i] * 2 > N) { return getCentroid(i, adj, node); } } return node; } void findDepth(int node, int parent, int sub, int dep, vector<vector<int>> &adj, vector<int> &depth) { if (sub == -2) sub = -1; else if (sub == -1) sub = node; subt[sub].insert(node); depth[node] = dep; for (auto neighbor : adj[node]) { if (neighbor == parent) continue; findDepth(neighbor, node, sub, dep + 1, adj, depth); } } void minCase(int node, vector<vector<int>> &adj, vector<bool> &vis) { int parent = -1; for (auto neighbor : adj[node]) { if (depth[neighbor] < depth[node]) { parent = neighbor; break; } } // we are at an isolated root if (parent == -1) { vis[node] = true; mn += 2; swap(ansMin[node], ansMin[adj[node][0]]); } else { vis[parent] = true; for (auto neighbor : adj[parent]) { if (depth[neighbor] < depth[parent]) { continue; } if (vis[neighbor]) continue; vis[neighbor] = true; mn += 2; swap(ansMin[parent], ansMin[neighbor]); } } return; } void solution() { cin >> N; ansMin.resize(N), ansMax.resize(N), depth.resize(N), subtSz.resize(N); for (int i = 0; i < N; i++) { ansMin[i] = i; ansMax[i] = i; } vector<vector<int>> adj(N); for (int i = 0; i < N - 1; i++) { int u, v; cin >> u >> v; u--; v--; adj[u].push_back(v); adj[v].push_back(u); } getSubtrSz(0, adj); int centroid = getCentroid(0, adj); findDepth(centroid, -1, -2, 0, adj, depth); // min case vector<bool> vis(N, false); vector<pair<int, int>> depthCopy(N); for (int i = 0; i < N; i++) { depthCopy[i] = {depth[i], i}; } sort(rall(depthCopy)); for (int i = 0; i < N; i++) { if (!vis[depthCopy[i].second]) { minCase(depthCopy[i].second, adj, vis); } } // max case vis.assign(N, false); depthCopy.clear(), depthCopy.resize(N); for (int i = 0; i < N; i++) { depthCopy.push_back({depth[i], i}); } sort(rall(depthCopy)); priority_queue<pair<int, int>> pq; for (auto x : adj[centroid]) { pq.push({subt[x].size(), x}); } // pair subtrees together bool flag = false; while (!pq.empty()) { pair<int, int> fir = pq.top(); pq.pop(); if (pq.empty()) {flag = true; pq.push(fir); break;} pair<int, int> sec = pq.top(); pq.pop(); auto ele1 = subt[fir.second].begin(), ele2 = subt[sec.second].begin(); swap(ansMax[*ele1], ansMax[*ele2]); mx += depth[*ele1] + depth[*ele2]; subt[fir.second].erase(ele1); subt[sec.second].erase(ele2); fir.first--; sec.first--; if (fir.first > 0) pq.push(fir); if (sec.first > 0) pq.push(sec); } if (flag) { auto ele1 = subt[pq.top().second].begin(); int ele2 = centroid; swap(ansMax[*ele1], ansMax[ele2]); mx += depth[*ele1] + depth[ele2]; } else { swap(ansMax[centroid], ansMax[adj[centroid][0]]); } // print the answer cout << mn sp mx * 2 << endl; for (int x : ansMin) cout << x + 1 << " "; cout << endl; for (int x : ansMax) cout << x + 1 << " "; cout << endl; return; } signed main() { fast_io(); solution(); return 0; }
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