Submission #1177688

#	Time	Username	Problem	Language	Result	Execution time	Memory
1177688		mychecksedad	Jail (JOI22_jail)	C++20	5 / 100	5086 ms	413088 KiB

jail

/* Author : Mychecksdead  */
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define pb push_back
#define all(x) x.begin(), x.end()
#define en cout << '\n'
#define ff first
#define ss second
#define pii pair<int,int>
#define vi vector<int>
const int N = 1e6+100, M = 1e5+10, K = 52, MX = 30;


int n, m, a[N][2], tin[N], tout[N], timer = 0;
vi g[N], A[N], B[N], G[N];
int cur, curv;
bool dead;
vector<vector<bool>> go;
void pre(int v, int p){
  tin[v] = timer++;
  for(int u: g[v]){
    if(u != p){
      pre(u, v);
    }
  }
  tout[v] = timer++;
}
bool dfs(int v, int p, int t){
  if(v == t){
    for(int x: A[v]) go[cur][x] = 1;
    return true;
  }
  for(int u: g[v]){
    if(u != p){
      bool ok = dfs(u, v, t);
      if(ok){
        //process v, it's a node the path of cur
        if(curv != v){
          for(int x: A[v]){
            go[cur][x] = 1;
          }
        }
        for(int x: B[v]) go[x][cur] = 1;
        return true;
      }
    }
  }
  return false;
}
void dfs2(int v, vector<int> &vis){
  vis[v] = 1;
  for(int u: G[v]){
    if(vis[u] == 2) continue;
    if(vis[u] == 1){
      dead = 1;
      return;
    }
    dfs2(u, vis);
  }
  vis[v] = 2;
}
void solve(){
  cin >> n;
  for(int i = 1; i <= n; ++i) g[i].clear();
  for(int i = 1; i <= n; ++i) A[i].clear();
  for(int i = 1; i <= n; ++i) B[i].clear();
  for(int i = 1; i <= n; ++i) G[i].clear();
  go.clear();
  for(int i = 1; i < n; ++i){
    int u, v; cin >> u >> v;
    g[u].pb(v);
    g[v].pb(u);
  }
  cin >> m;
  go.resize(m + 2, vector<bool>(m + 2));
  for(int i = 1; i <= m; ++i){
    cin >> a[i][0] >> a[i][1];
    A[a[i][0]].pb(i);
    B[a[i][1]].pb(i);
  }
  for(int i = 1; i <= m; ++i){
    cur = i;
    curv = a[i][0];
    dfs(a[i][0], a[i][0], a[i][1]);
  }
  vector<int> vis(m + 1);
  dead = 0;
  for(int i = 1; i <= m; ++i){
    for(int j = i + 1; j <= m; ++j) dead |= (go[i][j] && go[j][i]);
  }
  if(dead) cout << "No";
  else cout << "Yes";
}


int main(){
  cin.tie(0); ios::sync_with_stdio(0);
  int tt = 1, aa;
  // freopen("in.txt", "r", stdin);
  // freopen("out.txt", "w", stdout);
  cin >> tt;
  while(tt--){
    solve();
    en;
  }
  cerr<<"time taken : "<<(float)clock()/CLOCKS_PER_SEC<<" seconds\n";
  return 0;
} 

• Subtask 1: 0 / 5
• Subtask 2: 5 / 5
• Subtask 3: 0 / 16
• Subtask 4: 0 / 28
• Subtask 5: 0 / 12
• Subtask 6: 0 / 11
• Subtask 7: 0 / 23