#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e5 + 5;
int n, m, p;
vector<int> adj[MAXN];
int a[MAXN], b[MAXN];
int x[MAXN], y[MAXN];
int Time;
int dfn[MAXN], low[MAXN];
map<pair<int, int>, bool> bridge;
void dfs(int cur, int p = -1) {
dfn[cur] = low[cur] = ++Time;
for (int v : adj[cur]) {
if (!dfn[v]) {
dfs(v, cur);
low[cur] = min(low[cur], low[v]);
if (low[v] > dfn[cur] && cnt[make_pair(cur, v)] == 1) {
bridge[make_pair(cur, v)] = bridge[make_pair(v, cur)] = true;
}
} else if (dfn[v] < dfn[cur]) {
low[cur] = min(low[cur], dfn[v]);
}
}
}
bitset<MAXN> vis;
int n_blocks;
int block[MAXN];
void dfs2(int cur, int p = -1) {
vis[cur] = 1;
if (p != -1) {
block[cur] = block[p];
}
for (int v : adj[cur]) if (v != p) {
if (!vis[v] && !bridge[make_pair(cur, v)]) {
dfs2(v, cur);
}
}
}
set<int> tadj[MAXN];
int pre[MAXN];
map<pair<int, int>, char> mp;
int dfs3(int cur, int p = -1) {
vis[cur] = 1;
int val = pre[cur];
for (int v : tadj[cur]) if (v != p) {
val += dfs3(v, cur);
}
pair<int, int> pi = make_pair(p, cur);
pair<int, int> rv = make_pair(cur, p);
if (val < 0) {
mp[pi] = 'L';
mp[rv] = 'R';
} else if (val > 0) {
mp[pi] = 'R';
mp[rv] = 'L';
} else {
mp[pi] = mp[rv] = 'B';
}
return val;
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cin >> n >> m;
for (int i = 1; i <= m; i++) {
cin >> a[i] >> b[i];
adj[a[i]].push_back(b[i]);
adj[b[i]].push_back(a[i]);
cnt[make_pair(a[i], b[i])]++;
cnt[make_pair(b[i], a[i])]++;
}
cin >> p;
for (int i = 1; i <= p; i++) {
cin >> x[i] >> y[i];
}
for (int i = 1; i <= n; i++) {
if (!dfn[i]) {
dfs(i);
}
}
for (int i = 1; i <= n; i++) {
if (!vis[i]) {
block[i] = ++n_blocks;
dfs2(i);
}
}
for (int i = 1; i <= m; i++) {
int A = block[a[i]];
int B = block[b[i]];
if (A != B) { // bridge
tadj[A].insert(B);
tadj[B].insert(A);
}
}
for (int i = 1; i <= p; i++) {
int u = block[x[i]];
int v = block[y[i]];
if (u == v) {
continue;
}
pre[u]--;
pre[v]++;
}
vis.reset();
for (int i = 1; i <= n; i++) {
if (!vis[i]) {
dfs3(i);
}
}
for (int i = 1; i <= m; i++) {
int u = block[a[i]];
int v = block[b[i]];
if (u == v) {
cout << 'B';
} else {
cout << mp[make_pair(u, v)];
}
}
cout << endl;
return 0;
}
Compilation message
oneway.cpp: In function 'void dfs(int, int)':
oneway.cpp:21:29: error: 'cnt' was not declared in this scope
if (low[v] > dfn[cur] && cnt[make_pair(cur, v)] == 1) {
^~~
oneway.cpp:21:29: note: suggested alternative: 'int'
if (low[v] > dfn[cur] && cnt[make_pair(cur, v)] == 1) {
^~~
int
oneway.cpp: In function 'int main()':
oneway.cpp:79:3: error: 'cnt' was not declared in this scope
cnt[make_pair(a[i], b[i])]++;
^~~
oneway.cpp:79:3: note: suggested alternative: 'int'
cnt[make_pair(a[i], b[i])]++;
^~~
int
