oj.uz

Submission #564060

# Submission time Handle Problem Language Result Execution time Memory
564060 2022-05-18T13:57:47 Z hoanghq2004 One-Way Streets (CEOI17_oneway) C++14
100 / 100
 80 ms 20544 KB 
#include <bits/stdc++.h>
 
using namespace std;
 
const int N = 1e5 + 10;
 
int n, m, cnt, q;
vector <int> e[N], stk;
vector <pair <int, int> > g[N];
int num[N], low[N], ti, comp[N], w[N];
 
void dfs(int u, int p) {
    stk.push_back(u);
    low[u] = num[u] = ++ti;
    for (int i = 0; i < g[u].size(); ++i) {
        int v = g[u][i].first;
        int id = g[u][i].second;
        if (id == p) continue;
        if (comp[v]) continue;
        if (!num[v]) {
            dfs(v, id);
            low[u] = min(low[u], low[v]);
        } else low[u] = min(low[u], num[v]);
    }
    if (low[u] == num[u]) {
        ++m;
        while (stk.size()) {
            int v = stk.back();
            stk.pop_back();
            comp[v] = m;
            for (auto w: g[v]) {
                if (comp[w.first] && m != comp[w.first]) e[m].push_back(comp[w.first]);
            }
            if (v == u) break;
        }
    }
}
 
void pull(int u) {
    num[u] = 1;
    for (auto v: e[u]) {
        if (!num[v]) pull(v);
        w[u] += w[v];
    }
}
 
int main() {
    ios :: sync_with_stdio(0); cin.tie(0);
    cin >> n >> m;
    vector <pair <int, int> > edges;
    for (int i = 1; i <= m; ++i) {
        int u, v;
        cin >> u >> v;
        g[u].push_back({v, i});
        g[v].push_back({u, i});
        edges.push_back({u, v});
    }
    m = 0;
    for (int i = 1; i <= n; ++i) {
        if (num[i]) continue;
        dfs(i, 0);
    }
    cin >> q;
    while (q--) {
        int u, v;
        cin >> u >> v;
        u = comp[u], v = comp[v];
        if (u == v) continue;
        ++w[u], --w[v];
    }
    memset(num, 0, sizeof(num));
    for (int i = 1; i <= m; ++i) {
        if (num[i]) continue;
        pull(i);
    }
    for (int i = 0; i < edges.size(); ++i) {
        int u = edges[i].first;
        int v = edges[i].second;
        u = comp[u], v = comp[v];
        if (u == v) {
            cout << 'B';
            continue;
        }
        if (u > v) {
            if (w[v] < 0) cout << 'R';
            if (w[v] > 0) cout << 'L';
            if (w[v] == 0) cout << 'B';
        } else {
            if (w[u] < 0) cout << 'L';
            if (w[u] > 0) cout << 'R';
            if (w[u] == 0) cout << 'B';
        }
    }
}

Compilation message

oneway.cpp: In function 'void dfs(int, int)':
oneway.cpp:15:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |     for (int i = 0; i < g[u].size(); ++i) {
      |                     ~~^~~~~~~~~~~~~
oneway.cpp: In function 'int main()':
oneway.cpp:76:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   76 |     for (int i = 0; i < edges.size(); ++i) {
      |                     ~~^~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5332 KB Output is correct
2 Correct 3 ms 5412 KB Output is correct
3 Correct 3 ms 5460 KB Output is correct
4 Correct 3 ms 5460 KB Output is correct
5 Correct 3 ms 5516 KB Output is correct
6 Correct 4 ms 5460 KB Output is correct
7 Correct 3 ms 5460 KB Output is correct
8 Correct 4 ms 5460 KB Output is correct
9 Correct 4 ms 5416 KB Output is correct
10 Correct 4 ms 5408 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5332 KB Output is correct
2 Correct 3 ms 5412 KB Output is correct
3 Correct 3 ms 5460 KB Output is correct
4 Correct 3 ms 5460 KB Output is correct
5 Correct 3 ms 5516 KB Output is correct
6 Correct 4 ms 5460 KB Output is correct
7 Correct 3 ms 5460 KB Output is correct
8 Correct 4 ms 5460 KB Output is correct
9 Correct 4 ms 5416 KB Output is correct
10 Correct 4 ms 5408 KB Output is correct
11 Correct 41 ms 11584 KB Output is correct
12 Correct 46 ms 12460 KB Output is correct
13 Correct 49 ms 13680 KB Output is correct
14 Correct 54 ms 14364 KB Output is correct
15 Correct 62 ms 14400 KB Output is correct
16 Correct 60 ms 13928 KB Output is correct
17 Correct 56 ms 16092 KB Output is correct
18 Correct 72 ms 13952 KB Output is correct
19 Correct 55 ms 17204 KB Output is correct
20 Correct 43 ms 12280 KB Output is correct
21 Correct 42 ms 11928 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5332 KB Output is correct
2 Correct 3 ms 5412 KB Output is correct
3 Correct 3 ms 5460 KB Output is correct
4 Correct 3 ms 5460 KB Output is correct
5 Correct 3 ms 5516 KB Output is correct
6 Correct 4 ms 5460 KB Output is correct
7 Correct 3 ms 5460 KB Output is correct
8 Correct 4 ms 5460 KB Output is correct
9 Correct 4 ms 5416 KB Output is correct
10 Correct 4 ms 5408 KB Output is correct
11 Correct 41 ms 11584 KB Output is correct
12 Correct 46 ms 12460 KB Output is correct
13 Correct 49 ms 13680 KB Output is correct
14 Correct 54 ms 14364 KB Output is correct
15 Correct 62 ms 14400 KB Output is correct
16 Correct 60 ms 13928 KB Output is correct
17 Correct 56 ms 16092 KB Output is correct
18 Correct 72 ms 13952 KB Output is correct
19 Correct 55 ms 17204 KB Output is correct
20 Correct 43 ms 12280 KB Output is correct
21 Correct 42 ms 11928 KB Output is correct
22 Correct 76 ms 17276 KB Output is correct
23 Correct 80 ms 15452 KB Output is correct
24 Correct 77 ms 15104 KB Output is correct
25 Correct 72 ms 20544 KB Output is correct
26 Correct 71 ms 16636 KB Output is correct
27 Correct 69 ms 15420 KB Output is correct
28 Correct 30 ms 9448 KB Output is correct
29 Correct 60 ms 12848 KB Output is correct
30 Correct 57 ms 13112 KB Output is correct
31 Correct 57 ms 13396 KB Output is correct
32 Correct 59 ms 16060 KB Output is correct