Submission #645102

#	Time	Username	Problem	Language	Result	Execution time	Memory
645102		dattranxxx	Split the Attractions (IOI19_split)	C++17	18 / 100	109 ms	26180 KiB

split

#include "split.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 1e5 + 5;
vector<int> adj[N];
int n, m;
vector<int> result;
vector<int> impossible() {
  for (int v = 0; v < n; ++v)
    result.emplace_back(0);
  return result;
}
int R = -1, t = 0; pair<int, int> x[3];
int low[N], in[N], siz[N];
vector<int> tri[N];
void build(int u) {
  in[u] = low[u] = ++t;
  int flag = 1; siz[u] = 1;
  for (int v : adj[u]) 
    if (in[v]) low[u] = min(low[u], in[v]);
    else tri[u].emplace_back(v), build(v), 
         low[u] = min(low[u], low[v]), siz[u] += siz[v], flag &= siz[v] < x[0].first;
  flag &= siz[u] >= x[0].first;
  if (flag) R = u;
}
int res[N], ans[N];
void dfs(int u, int c) {
  ans[u] = c;
  for (int v : tri[u])  
    dfs(v, c);
}
int fixx(int u) {
  res[u] = x[0].second; x[0].first--;
  if (x[0].first == 0) return 1;
  for (int v : tri[u]) if (ans[v] == x[0].second) {
    if (fixx(v)) return 1;
  }
  return 0;
}
int fixy(int u) {
  res[u] = x[1].second; x[1].first--;
  if (x[1].first == 0) return 1;
  for (int v : tri[u]) if (ans[v] == x[2].second) {
    if (fixy(v)) return 1;
  }
  return 0;
}
vector<int> print() {
  for (int v = 0; v < n; ++v) res[v] = x[2].second;
  fixx(R); fixy(0);
  for (int v = 0; v < n; ++v)
    result.emplace_back(res[v]);
  return result;
}
int P1, P2;
void dfs2(int u) {
  for (int v : tri[u]) if (low[v] < in[R]) {
    if (P1 - siz[v] >= x[0].first)
      P1 -= siz[v], dfs(v, x[2].second);
    else dfs2(v);
  }
}

vector<int> find_split(int _n, int a, int b, int c, vector<int> p, vector<int> q) {
  n = _n, m = p.size();
  x[0] = {a, 1}, x[1] = {b, 2}, x[2] = {c, 3};
  for (int i = 0, u, v; i < m; ++i)
    u = p[i], v = q[i],
    adj[u].emplace_back(v),
    adj[v].emplace_back(u);
  build(0);
  if (R == -1) return impossible();
  for (int v = 0; v < n; ++v) 
    ans[v] = x[2].second;
  dfs(R, x[0].second);
  int P1 = siz[R], P2 = n - P1;
  dfs2(R);
  if (P2 < x[0].first) return impossible();
  return print();
}

• Subtask 1: 7 / 7
• Subtask 2: 11 / 11
• Subtask 3: 0 / 22
• Subtask 4: 0 / 24
• Subtask 5: 0 / 36