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Submission #1085541

# Submission time Handle Problem Language Result Execution time Memory
1085541 2024-09-08T11:49:36 Z juicy One-Way Streets (CEOI17_oneway) C++17
100 / 100
 54 ms 21948 KB 
#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif

const int N = 1e5 + 5;

int n, m, p;
int low[N], num[N], lab[N], a[N], ind[N];
vector<int> g[N];
vector<array<int, 2>> tr[N];

int timer;
vector<int> st;

void dfs(int u, int p) {
  low[u] = num[u] = ++timer;
  st.push_back(u);
  bool rep = 0;
  for (int v : g[u]) {
    if (v == p && !rep) {
      rep = 1;
      continue;
    } 
    if (!low[v]) {
      dfs(v, u);
      low[u] = min(low[u], low[v]);
    } else {
      low[u] = min(low[u], num[v]);
    }
  }
  if (low[u] == num[u]) {
    while (1) {
      int v = st.back(); st.pop_back();
      lab[v] = u;
      if (v == u) {
        break;
      }
    }
  }
}

void DFS(int u, int p) {
  for (auto [v, id] : tr[u]) {
    if (v ^ p) {
      ind[v] = id;
      DFS(v, u);
      a[u] += a[v];
    }
  }
}

int main() {
  ios::sync_with_stdio(false); cin.tie(nullptr);

  cin >> n >> m;
  string res(m, 'B');
  vector<array<int, 2>> e(m);
  for (int i = 0; i < m; ++i) {
    int u, v; cin >> u >> v;
    e[i] = {u, v};
    g[u].push_back(v);
    g[v].push_back(u);
  }  
  for (int i = 1; i <= n; ++i) {
    if (!num[i]) {
      dfs(i, i);
    }
  }
  for (int i = 0; i < m; ++i) {
    auto [u, v] = e[i];
    tie(u, v) = tie(lab[u], lab[v]);
    if (u ^ v) {
      tr[u].push_back({v, -1 - i});
      tr[v].push_back({u, i + 1});
    }
  }
  cin >> p;
  while (p--) {
    int x, y; cin >> x >> y;
    ++a[lab[x]], --a[lab[y]];
  }
  for (int i = 1; i <= n; ++i) {
    if (!ind[i]) {
      DFS(i, i);
    }
  }
  for (int i = 2; i <= n; ++i) {
    if (a[i]) {
      bool r = (a[i] > 0) ^ (ind[i] < 0);
      int id = abs(ind[i]) - 1;
      res[id] = r ? 'R' : 'L';
    }
  }
  cout << res;
  return 0;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 6748 KB Output is correct
2 Correct 1 ms 6748 KB Output is correct
3 Correct 2 ms 6748 KB Output is correct
4 Correct 2 ms 6748 KB Output is correct
5 Correct 2 ms 6796 KB Output is correct
6 Correct 2 ms 6804 KB Output is correct
7 Correct 2 ms 6744 KB Output is correct
8 Correct 2 ms 6800 KB Output is correct
9 Correct 1 ms 6748 KB Output is correct
10 Correct 1 ms 6748 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 6748 KB Output is correct
2 Correct 1 ms 6748 KB Output is correct
3 Correct 2 ms 6748 KB Output is correct
4 Correct 2 ms 6748 KB Output is correct
5 Correct 2 ms 6796 KB Output is correct
6 Correct 2 ms 6804 KB Output is correct
7 Correct 2 ms 6744 KB Output is correct
8 Correct 2 ms 6800 KB Output is correct
9 Correct 1 ms 6748 KB Output is correct
10 Correct 1 ms 6748 KB Output is correct
11 Correct 21 ms 11612 KB Output is correct
12 Correct 24 ms 12656 KB Output is correct
13 Correct 28 ms 13776 KB Output is correct
14 Correct 32 ms 14740 KB Output is correct
15 Correct 32 ms 15320 KB Output is correct
16 Correct 38 ms 16212 KB Output is correct
17 Correct 39 ms 17760 KB Output is correct
18 Correct 35 ms 16208 KB Output is correct
19 Correct 36 ms 18892 KB Output is correct
20 Correct 24 ms 12508 KB Output is correct
21 Correct 21 ms 12124 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 6748 KB Output is correct
2 Correct 1 ms 6748 KB Output is correct
3 Correct 2 ms 6748 KB Output is correct
4 Correct 2 ms 6748 KB Output is correct
5 Correct 2 ms 6796 KB Output is correct
6 Correct 2 ms 6804 KB Output is correct
7 Correct 2 ms 6744 KB Output is correct
8 Correct 2 ms 6800 KB Output is correct
9 Correct 1 ms 6748 KB Output is correct
10 Correct 1 ms 6748 KB Output is correct
11 Correct 21 ms 11612 KB Output is correct
12 Correct 24 ms 12656 KB Output is correct
13 Correct 28 ms 13776 KB Output is correct
14 Correct 32 ms 14740 KB Output is correct
15 Correct 32 ms 15320 KB Output is correct
16 Correct 38 ms 16212 KB Output is correct
17 Correct 39 ms 17760 KB Output is correct
18 Correct 35 ms 16208 KB Output is correct
19 Correct 36 ms 18892 KB Output is correct
20 Correct 24 ms 12508 KB Output is correct
21 Correct 21 ms 12124 KB Output is correct
22 Correct 47 ms 18768 KB Output is correct
23 Correct 48 ms 17236 KB Output is correct
24 Correct 54 ms 17232 KB Output is correct
25 Correct 52 ms 21948 KB Output is correct
26 Correct 50 ms 18372 KB Output is correct
27 Correct 53 ms 17236 KB Output is correct
28 Correct 22 ms 10076 KB Output is correct
29 Correct 32 ms 13172 KB Output is correct
30 Correct 33 ms 13272 KB Output is correct
31 Correct 35 ms 13520 KB Output is correct
32 Correct 38 ms 16340 KB Output is correct