#include <algorithm>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#ifdef DEBUG
#include <time.h>
#endif
#define all(a) (a).begin(), (a).end()
#define rev(a) (a).rbegin(), (a).rend()
#define F first
#define S second
int recur_depth = 0;
#ifdef DEBUG
#define dbg(x) \
{ \
++recur_depth; \
auto x_ = x; \
--recur_depth; \
cerr << string(recur_depth, '\t') << "\e[91m" << __func__ << ":" \
<< __LINE__ << "\t" << #x << " = " << x_ << "\e[39m" << endl; \
}
#else
#define dbg(x)
#endif
using namespace std;
using namespace __gnu_pbds;
typedef pair<int, int> ii;
typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> llll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pair<int, int>> vii;
typedef vector<vii> vvii;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<pair<ll, ll>> vll;
typedef vector<vll> vvll;
typedef vector<bool> vb;
template <class type1>
using ordered_set = tree<type1, null_type, less<type1>, rb_tree_tag,
tree_order_statistics_node_update>;
template <typename A, typename B>
ostream &operator<<(ostream &os, const pair<A, B> &p) {
return os << '(' << p.first << ", " << p.second << ')';
}
template <typename T_container, typename T = typename enable_if<
!is_same<T_container, string>::value,
typename T_container::value_type>::type>
ostream &operator<<(ostream &os, const T_container &v) {
os << '{';
string sep;
for (const T &x : v)
os << sep << x, sep = ", ";
return os << '}';
}
const ll MOD = 1e9 + 7;
// const ll MOD = 998244353;
const ll INF = 1e9;
const ld EPS = 1e-9;
struct ST {
const int MAXLG = 22;
int n;
vvii st;
vi lg2;
ST(vii a) : n(a.size()) {
lg2 = vi(n + 10);
lg2[1] = 0;
for (int i = 2; i <= n; i++)
lg2[i] = lg2[i / 2] + 1;
st = vvii(MAXLG, vii(n));
st[0] = a;
for (int j = 1; j < MAXLG; j++)
for (int i = 0; i + (1 << j) <= n; i++)
st[j][i] = min(st[j - 1][i], st[j - 1][i + (1 << (j - 1))]);
}
int query(int l, int r) {
if (l > r)
swap(l, r);
int k = lg2[r - l + 1];
return min(st[k][l], st[k][r - (1 << k) + 1]).second;
}
};
struct DSU {
int n;
vi par, sz;
int no_cc;
DSU(int n) : n(n), par(vi(n, -1)), sz(vi(n, 1)), no_cc(n) {}
int find(int x) {
if (par[x] == -1)
return x;
return par[x] = find(par[x]);
}
void merge(int u, int v) {
u = find(u), v = find(v);
if (u == v)
return;
if (sz[u] < sz[v])
swap(u, v);
par[v] = u;
sz[u] += sz[v];
no_cc--;
}
};
struct Edge {
int u, v, idx, res;
bool is_bridge;
};
void solve() {
int n, m;
cin >> n >> m;
vvii adj(n);
vector<Edge> eds(m);
int i_ = 0;
for (auto &e : eds) {
cin >> e.u >> e.v;
e.u--, e.v--;
e.idx = i_++;
e.res = 2;
adj[e.u].push_back({e.v, e.idx});
adj[e.v].push_back({e.u, e.idx});
}
int p;
cin >> p;
vi st(p), en(p);
for (int i = 0; i < p; i++)
cin >> st[i] >> en[i], st[i]--, en[i]--;
int timer = 0;
vi tin(n), low(n);
vb vis(n);
function<void(int, int)> f = [&](int u, int p_e_id) {
vis[u] = 1;
tin[u] = low[u] = timer++;
for (auto [v, e_id] : adj[u])
if (e_id != p_e_id) {
if (vis[v])
low[u] = min(low[u], low[v]);
else {
f(v, e_id);
low[u] = min(low[u], low[v]);
if (low[v] > tin[u])
eds[e_id].is_bridge = 1;
}
}
};
for (int i = 0; i < n; i++)
if (!vis[i])
f(i, -1);
DSU d(n);
for (auto e : eds)
if (!e.is_bridge)
d.merge(e.u, e.v);
int new_idx = 0;
vi new_idxs(n, -1);
auto get_idx = [&](int x) {
x = d.find(x);
if (new_idxs[x] != -1)
return new_idxs[x];
return new_idxs[x] = new_idx++;
};
int nn = d.no_cc;
if (nn == 1) {
cout << string(m, 'B') << "\n";
return;
}
vvii tree(nn);
for (auto e : eds)
if (e.is_bridge)
tree[get_idx(e.u)].push_back({get_idx(e.v), e.idx}),
tree[get_idx(e.v)].push_back({get_idx(e.u), e.idx});
vi depth(nn), first_occ(nn, -1), cnt_child(nn);
vii euler, par(nn, {-1, -1});
vb nvis(nn);
function<void(int, int)> g = [&](int u, int p) {
nvis[u] = 1;
first_occ[u] = euler.size();
euler.emplace_back(depth[u], u);
for (auto [v, e] : tree[u])
if (v != p) {
par[v] = {u, e};
cnt_child[u]++;
depth[v] = depth[u] + 1;
g(v, u);
euler.emplace_back(depth[u], u);
}
};
int root = 0;
g(root, -1);
// cerr << euler << "\n";
// cerr << first_occ << "\n";
ST lc(euler);
for (int i = 0; i < nn; i++)
assert(nvis[i]);
vi no_st(nn), no_en(nn);
for (int i = 0; i < p; i++) {
int u = get_idx(st[i]), v = get_idx(en[i]);
if (u == v)
continue;
int lca = lc.query(first_occ[u], first_occ[v]);
no_st[u]++, no_en[v]++;
no_st[lca]--, no_en[lca]--;
}
queue<int> q;
for (int i = 0; i < nn; i++)
if (cnt_child[i] == 0 && i != root)
q.push(i);
while (!q.empty()) {
int u = q.front();
q.pop();
// cerr << "U: " << u << '\n';
// cerr << "\t" << no_st[u] << " " << no_en[u] << "\n";
auto [p, p_e_id] = par[u];
if (p < 0)
break;
assert(no_st[u] == 0 || no_en[u] == 0);
if (no_st[u] > 0) {
if (get_idx(eds[p_e_id].u) == u)
eds[p_e_id].res = 0;
else
eds[p_e_id].res = 1;
}
if (no_en[u] > 0) {
if (get_idx(eds[p_e_id].u) == u)
eds[p_e_id].res = 1;
else
eds[p_e_id].res = 0;
}
no_st[p] += no_st[u];
no_en[p] += no_en[u];
if (--cnt_child[p] == 0)
q.push(p);
}
for (int i = 0; i < m; i++) {
if (eds[i].res == 0)
cout << "R";
else if (eds[i].res == 1)
cout << "L";
else
cout << "B";
}
cout << "\n";
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(NULL);
clock_t start = clock();
int test_cases = 1;
// cin >> test_cases;
while (test_cases--)
solve();
#ifdef DEBUG
cerr << fixed << setprecision(10)
<< "\nTime Taken: " << (double)(clock() - start) / CLOCKS_PER_SEC
<< "s\n";
#endif
return 0;
}
Compilation message
oneway.cpp: In function 'int main()':
oneway.cpp:311:11: warning: unused variable 'start' [-Wunused-variable]
311 | clock_t start = clock();
| ^~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
1 ms |
592 KB |
Execution killed with signal 6 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
1 ms |
592 KB |
Execution killed with signal 6 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
1 ms |
592 KB |
Execution killed with signal 6 |
| 2 |
Halted |
0 ms |
0 KB |
- |
