#include<iostream>
#include<queue>
#include<stack>
#include<set>
#include<algorithm>
#include<string.h>
#include<map>
#define int long long
#define size() size() * 1ll
#define all(x) (x).begin(), (x).end()
#define allr(x, sz) (x) + 1, (x) + 1 + sz
#define pb push_back
#define pii pair<int,int>
#define fi first
#define se second
#define MASK(x) (1LL<<(x))
#define BIT(x,i) (((x)>>(i))&1)
#define numbit(x) __builtin_popcountll(x)
using namespace std;
const int N = 1e5 + 1;
const int M = 1e3 + 1;
const long long mod = 1e9 + 7;
const long long oo = 1e18 + 7;
typedef vector<int> vi;
typedef vector<pii> vii;
typedef long long ll;
template<class t>
bool mini(t &x,t y) {
if (x > y) {
x = y;
return 1;
}
return 0;
}
template<class t>
bool maxi(t &x,t y) {
if (x < y) {
x = y;
return 1;
}
return 0;
}
void file() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
//freopen(task.in, r, stdin);
//freopen(task.out, w, stdout);
return ;
}
int n, m, p;
pii e[N];
vi a[N], adj[N];
map<pii, int> mp, mp1;
stack<int> st;
int num[N], low[N];
void dfs(int u, int chu) {
st.push(u);
num[u] = low[u] = ++num[0];
for (auto v: a[u]) if (v != chu) {
if (num[v]) mini(low[u], num[v]); else {
dfs(v, u);
mini(low[u], low[v]);
}
}
if (num[u] == low[u]) {
int v;
low[0]++;
do {
v = st.top(), st.pop();
num[v] = low[v] = mod + low[0];
} while (v != u);
}
}
const int K = 30;
int cha[N], h[N], sub[N], heavy[N], head[N], pos[N];
void dfs1(int u, int chu) {
sub[u] = 1;
cha[u] = chu;
int cmax = -1;
for (auto v: adj[u]) if (v != chu) {
dfs1(v, u);
maxi(h[u], h[v] + 1);
sub[u] += sub[v];
if (maxi(cmax, sub[v])) {
heavy[u] = v;
}
}
}
void hld(int u, int h) {
pos[u] = ++pos[0];
num[pos[0]] = u;
head[u] = h;
if (heavy[u]) hld(heavy[u], h);
for (auto v: adj[u]) if (v != cha[u]) {
if (v != heavy[u]) hld(v, v);
}
}
int lca(int a, int b) {
while (head[a] != head[b]) {
if (h[head[a]] < h[head[b]]) swap(a, b);
a = cha[head[a]];
}
if (h[a] < h[b]) swap(a, b);
return a;
}
struct IT {
int n;
vii st;
IT(const int &_n = 0): n(_n + 1), st(4 *_n + 1, pii(0, 0)) {}
void down(int id) {
int x = st[id].se;
if (x == 0) return ;
st[id << 1].fi = x;
st[id << 1].se = x;
st[id << 1 | 1].fi = x;
st[id << 1 | 1].se = x;
x = 0;
}
int merge(int x, int y) {
if (x == 0) return y;
return x;
}
void adj(int id, int l, int r, int u, int v, int val) {
if (r < u || v < l) return ;
if (u <= l && r <= v) {
st[id].fi = val;
st[id].se = val;
return ;
}
int mid = (l + r) >> 1;
down(id);
adj(id << 1, l, mid, u, v, val);
adj(id << 1 | 1, mid + 1, r, u, v, val);
st[id].fi = merge(st[id << 1].fi, st[id << 1 | 1].fi);
}
int get(int id, int l, int r, int i) {
if (r < i || i < l) return 0;
if (l == r) return st[id].fi;
int mid = (l + r) >> 1;
down(id);
return merge(get(id << 1, l, mid, i), get(id << 1 | 1, mid + 1, r, i));
}
} it;
void lef(int a, int b) {
while (head[a] != head[b]) {
int x = head[a];
it.adj(1, 1, n, pos[x], pos[a], 1);
a = cha[x];
}
it.adj(1, 1, n, pos[b], pos[a], 1);
}
void rig(int a, int b) {
while (head[a] != head[b]) {
int x = head[a];
it.adj(1, 1, n, pos[x], pos[a], -1);
a = cha[x];
}
it.adj(1, 1, n, pos[b], pos[a], -1);
}
void solve(int test = -1) {
cin >> n >> m;
for (int i = 1; i <= m; i++) {
int x, y;
cin >> x >> y;
a[x].pb(y);
a[y].pb(x);
e[i] = pii(x, y);
}
for (int i = 1; i <= n; i++) if (!num[i]);
dfs(1, 0);
num[0] = 0;
for (int i = 1; i <= n; i++) {
num[i] = 0;
for (auto v: a[i]) {
if (low[i] != low[v]) {
adj[low[i] - mod].pb(low[v] - mod);
}
}
}
for (int i = 1; i <= low[0]; i++) {
dfs1(i, 0);
hld(i, 0);
}
it = IT(low[0]);
cin >> p;
for (int i = 1; i <= p; i++) {
int x, y;
cin >> x >> y;
x = low[x] - mod;
y = low[y] - mod;
int par = lca(x, y);
lef(x, par);
rig(y, par);
}
for (int i = 2; i <= n; i++) {
int v = num[i];
int u = cha[v];
int x = it.get(1, 1, n, i);
mp[pii(v, u)] = x;
mp[pii(u, v)] = -x;
}
for (int i = 1; i <= n; i++) {
for (auto v: a[i]) {
mp1[pii(i, v)] = mp[pii(low[i] - mod, low[v] - mod)];
}
}
for (int i = 1; i <= m; i++) {
int u = e[i].fi;
int v = e[i].se;
cout << (mp1[pii(u, v)] == 0 ? "B" : mp1[pii(u, v)] == 1 ? "R" : "L");
}
}
int32_t main() {
file();
int T = 1;
// cin >> T;
for (int i = 1; i <= T; i++) {
solve(i);
}
return 0;
}
Compilation message
oneway.cpp: In function 'void solve(long long int)':
oneway.cpp:184:34: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
184 | for (int i = 1; i <= n; i++) if (!num[i]);
| ^~
oneway.cpp:185:9: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
185 | dfs(1, 0);
| ^~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
12 ms |
14036 KB |
Execution killed with signal 11 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
12 ms |
14036 KB |
Execution killed with signal 11 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
12 ms |
14036 KB |
Execution killed with signal 11 |
| 2 |
Halted |
0 ms |
0 KB |
- |
