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Submission #490991

# Submission time Handle Problem Language Result Execution time Memory
490991 2021-11-30T02:59:24 Z Rainbowbunny One-Way Streets (CEOI17_oneway) C++17
100 / 100
 82 ms 15864 KB 
#include <bits/stdc++.h>
using namespace std;
 
const int MAXN = 1e5 + 5;
const int MAXL = 20;
 
int n, m, q, tim;
int tin[MAXN], low[MAXN], com[MAXN], u[MAXN], v[MAXN], dp[MAXN];
bool Vis[MAXN];
char ans[MAXN];
vector <pair <int, int> > Adj[MAXN];
bool Bridge[MAXN];
 
void Build(int node, int p = -1)
{
    tim++;
    tin[node] = tim;
    low[node] = tim;
    Vis[node] = true;
    for(auto x : Adj[node])
    {
        if(x.second == p)
        {
            continue;
        }
        if(Vis[x.first])
        {
            low[node] = min(low[node], tin[x.first]);
        }
        else
        {
            Build(x.first, x.second);
            if(low[x.first] > tin[node])
            {
                Bridge[x.second] = true;
            }
            low[node] = min(low[node], low[x.first]);
        }
    }
}
 
void BuildNew(int node, int c)
{
    com[node] = c;
    for(auto x : Adj[node])
    {
        if(Bridge[x.second])
        {
            continue;
        }
        ans[x.second] = 'B';
        if(com[x.first])
        {
            continue;
        }
        BuildNew(x.first, c);
    }
}
 
void DFS(int node, int p = -1)
{
    Vis[node] = true;
    for(auto x : Adj[node])
    {
        if(x.first == p)
        {
            continue;
        }
        DFS(x.first, node);
    }
}
 
void DFS2(int node, int p = -1)
{
    Vis[node] = true;
    for(auto x : Adj[node])
    {
        if(x.first == p)
        {
            continue;
        }
        DFS2(x.first, node);
        if(dp[x.first] < 0)
        {
            ans[x.second] = (u[x.second] == node ? 'R' : 'L');
        }
        else if(dp[x.first] > 0)
        {
            ans[x.second] = (v[x.second] == node ? 'R' : 'L');
        }
        else
        {
            ans[x.second] = 'B';
        }
        dp[node] += dp[x.first];
    }
}
 
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        cin >> u[i] >> v[i];
        Adj[u[i]].emplace_back(v[i], i);
        Adj[v[i]].emplace_back(u[i], i);
    }
    for(int i = 1; i <= n; i++)
    {
        if(!Vis[i])
        {
            Build(i);
        }
    }
    tim = 0;
    for(int i = 1; i <= n; i++)
    {
        if(!com[i])
        {
            tim++;
            BuildNew(i, tim);
        }
    }
    for(int i = 1; i <= n; i++)
    {
        Adj[i].clear();
        Vis[i] = false;
    }
    for(int i = 1; i <= m; i++)
    {
        u[i] = com[u[i]], v[i] = com[v[i]];
        if(u[i] != v[i])
        {
            Adj[u[i]].emplace_back(v[i], i);
            Adj[v[i]].emplace_back(u[i], i);
        }
    }
    for(int i = 1; i <= tim; i++)
    {
        if(!Vis[i])
        {
            DFS(i);
        }
    }
    cin >> q;
    while(q--)
    {
        int x, y;
        cin >> x >> y;
        x = com[x];
        y = com[y];
        dp[x]++;
        dp[y]--;
    }
    for(int i = 1; i <= tim; i++)
    {
        Vis[i] = false;
    }
    for(int i = 1; i <= tim; i++)
    {
        if(!Vis[i])
        {
            DFS2(i);
        }
    }
    for(int i = 1; i <= m; i++)
    {
        cout << ans[i];
    }
    cout << '\n';
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 1 ms 2636 KB Output is correct
3 Correct 2 ms 2764 KB Output is correct
4 Correct 2 ms 2764 KB Output is correct
5 Correct 2 ms 2764 KB Output is correct
6 Correct 2 ms 2764 KB Output is correct
7 Correct 2 ms 2764 KB Output is correct
8 Correct 2 ms 2764 KB Output is correct
9 Correct 2 ms 2764 KB Output is correct
10 Correct 2 ms 2764 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 1 ms 2636 KB Output is correct
3 Correct 2 ms 2764 KB Output is correct
4 Correct 2 ms 2764 KB Output is correct
5 Correct 2 ms 2764 KB Output is correct
6 Correct 2 ms 2764 KB Output is correct
7 Correct 2 ms 2764 KB Output is correct
8 Correct 2 ms 2764 KB Output is correct
9 Correct 2 ms 2764 KB Output is correct
10 Correct 2 ms 2764 KB Output is correct
11 Correct 33 ms 8812 KB Output is correct
12 Correct 38 ms 9796 KB Output is correct
13 Correct 44 ms 11016 KB Output is correct
14 Correct 59 ms 12048 KB Output is correct
15 Correct 52 ms 12092 KB Output is correct
16 Correct 55 ms 10208 KB Output is correct
17 Correct 53 ms 11708 KB Output is correct
18 Correct 60 ms 10208 KB Output is correct
19 Correct 48 ms 12868 KB Output is correct
20 Correct 44 ms 9520 KB Output is correct
21 Correct 36 ms 9268 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 1 ms 2636 KB Output is correct
3 Correct 2 ms 2764 KB Output is correct
4 Correct 2 ms 2764 KB Output is correct
5 Correct 2 ms 2764 KB Output is correct
6 Correct 2 ms 2764 KB Output is correct
7 Correct 2 ms 2764 KB Output is correct
8 Correct 2 ms 2764 KB Output is correct
9 Correct 2 ms 2764 KB Output is correct
10 Correct 2 ms 2764 KB Output is correct
11 Correct 33 ms 8812 KB Output is correct
12 Correct 38 ms 9796 KB Output is correct
13 Correct 44 ms 11016 KB Output is correct
14 Correct 59 ms 12048 KB Output is correct
15 Correct 52 ms 12092 KB Output is correct
16 Correct 55 ms 10208 KB Output is correct
17 Correct 53 ms 11708 KB Output is correct
18 Correct 60 ms 10208 KB Output is correct
19 Correct 48 ms 12868 KB Output is correct
20 Correct 44 ms 9520 KB Output is correct
21 Correct 36 ms 9268 KB Output is correct
22 Correct 69 ms 12860 KB Output is correct
23 Correct 74 ms 11372 KB Output is correct
24 Correct 75 ms 11328 KB Output is correct
25 Correct 66 ms 15864 KB Output is correct
26 Correct 82 ms 12836 KB Output is correct
27 Correct 70 ms 11460 KB Output is correct
28 Correct 27 ms 6852 KB Output is correct
29 Correct 52 ms 10140 KB Output is correct
30 Correct 50 ms 10352 KB Output is correct
31 Correct 53 ms 10564 KB Output is correct
32 Correct 56 ms 12636 KB Output is correct