# | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
434057 | 2021-06-20T14:33:20 Z | kwongweng | Stations (IOI20_stations) | C++17 | 0 ms | 0 KB |
#include "stations.h" #include <bits/stdc++.h> using namespace std; typedef vector<int> vi; #define pb push_back vector<vi> g; vi ans, sz, d, used; int cur = 0; void dfs1(int u = 0, int p = -1){ for (int v : g[u]){ if (v == p) continue; d[v] = d[u] + 1; dfs1(v, u); sz[u] += sz[v] + 1; } } void dfs2(int u = 0, int p = -1){ if (d[u] % 2 == 0){ used[cur] = 1; ans[u] = cur; while (used[cur]) cur++; }else{ used[cur+sz[u]] = 1; ans[u] = cur+sz[u]; while (used[cur]) cur++; } for (int v : g[u]){ if (v == p) continue; dfs2(v, u); } } vi label(int n, int k, vi u, vi v) { g.resize(n); ans.resize(n); used.resize(n); d.resize(n); sz.resize(n); for (int i = 0; i < n-1; i++){ g[u[i]].pb(v[i]); g[v[i]].pb(u[i]); } dfs1(); dfs2(); return ans; }