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Submission #49113

# Submission time Handle Problem Language Result Execution time Memory
49113 2018-05-22T12:37:28 Z tmwilliamlin168 One-Way Streets (CEOI17_oneway) C++14
100 / 100
 334 ms 14076 KB 
#include <bits/stdc++.h>
using namespace std;

const int mxN=1e5;
int n, m, k, a[mxN], b[mxN], ab[mxN], d[mxN], s[mxN], p[mxN], r[mxN], dt=1, tin[mxN], low[mxN];
bool bg[mxN];
vector<int> adj[mxN];

int find(int x) {
	return x==p[x]?x:(p[x]=find(p[x]));
}

inline void join(int x, int y) {
	if((x=find(x))==(y=find(y)))
		return;
	if(r[x]<r[y])
		p[x]=y;
	else
		p[y]=x;
	if(r[x]==r[y])
		++r[x];
}

void dfs1(int u, int p) {
	tin[u]=low[u]=dt++;
	for(int e : adj[u]) {
		int v=u^ab[e];
		if(!tin[v]) {
			dfs1(v, e);
			low[u]=min(low[v], low[u]);
			if(low[v]>tin[u])
				bg[e]=1;
		} else if(e!=p)
			low[u]=min(tin[v], low[u]);
	}
}

void dfs2(int u, int p) {
	for(int e : adj[u]) {
		int v=u^ab[e];
		if(v==p)
			continue;
		d[v]=d[u]+1;
		dfs2(v, u);
		s[u]+=s[v];
	}
}

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n >> m;
	for(int i=0; i<n; ++i)
		p[i]=i;
	for(int i=0; i<m; ++i) {
		cin >> a[i] >> b[i], --a[i], --b[i];
		ab[i]=a[i]^b[i];
		adj[a[i]].push_back(i);
		adj[b[i]].push_back(i);
	}
	for(int i=0; i<n; ++i)
		if(!tin[i])
			dfs1(i, -1);
	for(int i=0; i<m; ++i)
		if(!bg[i])
			join(a[i], b[i]);
	for(int i=0; i<n; ++i)
		adj[i].clear();
	for(int i=0; i<m; ++i) {
		if(!bg[i])
			continue;
		a[i]=find(a[i]);
		b[i]=find(b[i]);
		ab[i]=a[i]^b[i];
		adj[a[i]].push_back(i);
		adj[b[i]].push_back(i);
	}
	cin >> k;
	while(k--) {
		int x, y;
		cin >> x >> y, --x, --y;
		++s[find(x)], --s[find(y)];
	}
	for(int i=0; i<n; ++i) {
		if(p[i]==i&&!d[i]) {
			d[i]=1;
			dfs2(i, -1);
		}
	}
	for(int i=0; i<m; ++i) {
		if(!bg[i]) {
			cout << 'B';
			continue;
		}
		int u=d[a[i]]>d[b[i]]?a[i]:b[i];
		cout << (s[u]?((s[u]>0)==(u==a[i])?'R':'L'):'B');
	}
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 2680 KB Output is correct
2 Correct 4 ms 2916 KB Output is correct
3 Correct 6 ms 2916 KB Output is correct
4 Correct 5 ms 2916 KB Output is correct
5 Correct 6 ms 2916 KB Output is correct
6 Correct 5 ms 2924 KB Output is correct
7 Correct 6 ms 2976 KB Output is correct
8 Correct 5 ms 3036 KB Output is correct
9 Correct 5 ms 3036 KB Output is correct
10 Correct 4 ms 3036 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 2680 KB Output is correct
2 Correct 4 ms 2916 KB Output is correct
3 Correct 6 ms 2916 KB Output is correct
4 Correct 5 ms 2916 KB Output is correct
5 Correct 6 ms 2916 KB Output is correct
6 Correct 5 ms 2924 KB Output is correct
7 Correct 6 ms 2976 KB Output is correct
8 Correct 5 ms 3036 KB Output is correct
9 Correct 5 ms 3036 KB Output is correct
10 Correct 4 ms 3036 KB Output is correct
11 Correct 50 ms 7220 KB Output is correct
12 Correct 61 ms 8536 KB Output is correct
13 Correct 70 ms 9924 KB Output is correct
14 Correct 107 ms 11220 KB Output is correct
15 Correct 191 ms 11476 KB Output is correct
16 Correct 120 ms 11476 KB Output is correct
17 Correct 112 ms 11476 KB Output is correct
18 Correct 92 ms 11476 KB Output is correct
19 Correct 111 ms 12392 KB Output is correct
20 Correct 75 ms 12392 KB Output is correct
21 Correct 56 ms 12392 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 2680 KB Output is correct
2 Correct 4 ms 2916 KB Output is correct
3 Correct 6 ms 2916 KB Output is correct
4 Correct 5 ms 2916 KB Output is correct
5 Correct 6 ms 2916 KB Output is correct
6 Correct 5 ms 2924 KB Output is correct
7 Correct 6 ms 2976 KB Output is correct
8 Correct 5 ms 3036 KB Output is correct
9 Correct 5 ms 3036 KB Output is correct
10 Correct 4 ms 3036 KB Output is correct
11 Correct 50 ms 7220 KB Output is correct
12 Correct 61 ms 8536 KB Output is correct
13 Correct 70 ms 9924 KB Output is correct
14 Correct 107 ms 11220 KB Output is correct
15 Correct 191 ms 11476 KB Output is correct
16 Correct 120 ms 11476 KB Output is correct
17 Correct 112 ms 11476 KB Output is correct
18 Correct 92 ms 11476 KB Output is correct
19 Correct 111 ms 12392 KB Output is correct
20 Correct 75 ms 12392 KB Output is correct
21 Correct 56 ms 12392 KB Output is correct
22 Correct 137 ms 12392 KB Output is correct
23 Correct 132 ms 12392 KB Output is correct
24 Correct 157 ms 12392 KB Output is correct
25 Correct 334 ms 14076 KB Output is correct
26 Correct 135 ms 14076 KB Output is correct
27 Correct 124 ms 14076 KB Output is correct
28 Correct 44 ms 14076 KB Output is correct
29 Correct 104 ms 14076 KB Output is correct
30 Correct 77 ms 14076 KB Output is correct
31 Correct 99 ms 14076 KB Output is correct
32 Correct 108 ms 14076 KB Output is correct