oj.uz

Submission #1090330

# Submission time Handle Problem Language Result Execution time Memory
1090330 2024-09-18T08:56:31 Z pmqwerty One-Way Streets (CEOI17_oneway) C++17
100 / 100
 69 ms 29860 KB 
#include<bits/stdc++.h>
using namespace std;
const int MAXN = 1e5 + 100;
const int MAX_LOG = 18;
vector<pair<int, int>> a[MAXN];
vector<pair<int, int>> bridges[MAXN];
vector<pair<int, int>> edges;
int parent[MAXN][MAX_LOG];
int tin[MAXN];
int tout[MAXN];
int components = 0;
int counter = 0;
int bridge = 0;
int num[MAXN];
int low[MAXN];
bool isBridge[MAXN];
int vis[MAXN];
int comp[MAXN];
int cnt[MAXN];
int ans[MAXN];
int inv[MAXN];
int n, m, p;
void dfs(int u, int p, int f){
    num[u] = low[u] = ++counter;
    for (auto x: a[u]){
         int v = x.first;
         if (x.second == f) continue;
         if (!num[v]){
             dfs(v, u, x.second);
             low[u] = min(low[u], low[v]);
             if (low[v] == num[v]){
                 bridge++;
                 isBridge[x.second] = true;
             }
         }
         else low[u] = min(low[u], num[v]);
    }
}
void dfs1(int u, int p){
    comp[u] = components;
    vis[u] = 1;
    for (auto v: a[u]){
         if (vis[v.first] || isBridge[v.second]) continue;
         dfs1(v.first, u);
    }
}
void dfs2(int u, int p){
    parent[u][0] = p;
    vis[u] = 1;
    for (auto x: bridges[u]){
         int v = x.first;
         if (v != p){
             inv[x.second] = (u != comp[edges[x.second].first]);
             dfs2(v, u);
         }
    }
}
void pre(){
    counter = 0;
    memset(vis, 0, sizeof(vis));
    for (int i = 1; i <= components; i++){
         if (!vis[i]) dfs2(i, i);
    }
}
void dfs3(int u, int p){
    vis[u] = 1;
    for (auto x: bridges[u]){
         int v = x.first;
         if (v == p) continue;
         dfs3(v, u);
         cnt[u] += cnt[v];
         if (cnt[v] > 0){
             ans[x.second] = 1;
         }
         else if (cnt[v] < 0){
             ans[x.second] = -1;
         }
    }
}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cin >> n >> m;
    for (int i = 0; i < m; i++){
         int x, y;
         cin >> x >> y;
         a[x].push_back({y, i});
         a[y].push_back({x, i});
         edges.push_back({x, y});
    }
    counter = 0;
    for (int i = 1; i <= n; i++){
        if (!num[i]){
             dfs(i, -1, -1);
        }
    }
    for (int i = 1; i <= n; i++){
         if (!vis[i]){
            components++;
            dfs1(i, -1);
         }
    }
    for (int i = 0; i < m; i++){
         if (isBridge[i]){
             bridges[comp[edges[i].first]].push_back({comp[edges[i].second], i});
             bridges[comp[edges[i].second]].push_back({comp[edges[i].first], i});
         }
    }
    pre();
    cin >> p;
    while (p--){
         int x, y;
         cin >> x >> y;
         x = comp[x];
         y = comp[y];
         cnt[x]++;
         cnt[y]--;
    }
    memset(vis,0 ,sizeof(vis));
    for (int i = 1; i <= components; i++){
         if (!vis[i]) dfs3(i, -1);
    }
    for (int i = 0; i < m; i++){
         if (inv[i]) ans[i] *= (-1);
         if (ans[i] == -1) cout << "R";
         else if (ans[i] == 1) cout << "L";
         else cout << "B";
    }
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5464 KB Output is correct
2 Correct 2 ms 5464 KB Output is correct
3 Correct 3 ms 5680 KB Output is correct
4 Correct 3 ms 5728 KB Output is correct
5 Correct 3 ms 5720 KB Output is correct
6 Correct 2 ms 5468 KB Output is correct
7 Correct 3 ms 5724 KB Output is correct
8 Correct 3 ms 5724 KB Output is correct
9 Correct 3 ms 5468 KB Output is correct
10 Correct 2 ms 5544 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5464 KB Output is correct
2 Correct 2 ms 5464 KB Output is correct
3 Correct 3 ms 5680 KB Output is correct
4 Correct 3 ms 5728 KB Output is correct
5 Correct 3 ms 5720 KB Output is correct
6 Correct 2 ms 5468 KB Output is correct
7 Correct 3 ms 5724 KB Output is correct
8 Correct 3 ms 5724 KB Output is correct
9 Correct 3 ms 5468 KB Output is correct
10 Correct 2 ms 5544 KB Output is correct
11 Correct 32 ms 11688 KB Output is correct
12 Correct 32 ms 13256 KB Output is correct
13 Correct 35 ms 14792 KB Output is correct
14 Correct 45 ms 17608 KB Output is correct
15 Correct 46 ms 18964 KB Output is correct
16 Correct 53 ms 24492 KB Output is correct
17 Correct 48 ms 25804 KB Output is correct
18 Correct 51 ms 24520 KB Output is correct
19 Correct 49 ms 26900 KB Output is correct
20 Correct 27 ms 12228 KB Output is correct
21 Correct 28 ms 12784 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5464 KB Output is correct
2 Correct 2 ms 5464 KB Output is correct
3 Correct 3 ms 5680 KB Output is correct
4 Correct 3 ms 5728 KB Output is correct
5 Correct 3 ms 5720 KB Output is correct
6 Correct 2 ms 5468 KB Output is correct
7 Correct 3 ms 5724 KB Output is correct
8 Correct 3 ms 5724 KB Output is correct
9 Correct 3 ms 5468 KB Output is correct
10 Correct 2 ms 5544 KB Output is correct
11 Correct 32 ms 11688 KB Output is correct
12 Correct 32 ms 13256 KB Output is correct
13 Correct 35 ms 14792 KB Output is correct
14 Correct 45 ms 17608 KB Output is correct
15 Correct 46 ms 18964 KB Output is correct
16 Correct 53 ms 24492 KB Output is correct
17 Correct 48 ms 25804 KB Output is correct
18 Correct 51 ms 24520 KB Output is correct
19 Correct 49 ms 26900 KB Output is correct
20 Correct 27 ms 12228 KB Output is correct
21 Correct 28 ms 12784 KB Output is correct
22 Correct 64 ms 26936 KB Output is correct
23 Correct 65 ms 25288 KB Output is correct
24 Correct 63 ms 25540 KB Output is correct
25 Correct 62 ms 29860 KB Output is correct
26 Correct 62 ms 26656 KB Output is correct
27 Correct 69 ms 25372 KB Output is correct
28 Correct 21 ms 9680 KB Output is correct
29 Correct 37 ms 12996 KB Output is correct
30 Correct 36 ms 13476 KB Output is correct
31 Correct 39 ms 13328 KB Output is correct
32 Correct 49 ms 19140 KB Output is correct