/**********************GOD**********************/
#include <iostream>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <cstdlib>
#include <string>
#include <vector>
#include <set>
#include <queue>
#include <stack>
#include <iterator>
#include <map>
using namespace std;
typedef long long ll;
typedef pair<ll , ll> pll;
#define len length()
#define MP make_pair
#define fs first
#define sc second
#define pb(x) push_back(x)
#define all(x) x.begin() , x.end()
#define kill(x) cout << x , exit(0)
const ll MAXN = 2e5 + 5;
const ll INF = 1e18 + 8;
const ll LOG = 23;
const ll mod = 1e9 + 7;
ll n , m , q;
vector<pll> adj[MAXN] , E;
ll dp[MAXN][2] , h[MAXN] , be[MAXN] , par[MAXN][LOG] , ans[MAXN];
bool mark[MAXN];
void DFS1(ll v)
{
for(ll i = 1 ; i < LOG ; i ++)
par[v][i] = par[par[v][i - 1]][i - 1];
mark[v] = 1;
be[v] = h[v];
for(auto[u , _] : adj[v])
{
if(!mark[u])
{
par[u][0] = v;
h[u] = h[v] + 1;
DFS1(u);
be[v] = min(be[v] , be[u]);
}
else if(h[u] + 1 < h[v])
be[v] = min(be[v] , h[u]);
else if(h[u] == h[v] + 1)
be[u] = min(be[u] , h[u] - 1);
}
}
void DFS2(ll v , ll id = 0)
{
mark[v] = 1;
for(auto[u , i] : adj[v])
if(!mark[u])
DFS2(u , i) ,
dp[v][0] += dp[u][0] , dp[v][1] += dp[u][1];
ans[id] = (dp[v][0] ? 2 : 3);
if(be[v] < h[v]) ans[id] = 1;
if(!dp[v][0] && !dp[v][1]) ans[id] = 1;
}
ll GetPar(ll v , ll k)
{
for(ll i = 0 ; i < LOG ; i ++){
if(k >> i & 1)
v = par[v][i];
}
return v;
}
ll LCA(ll v , ll u)
{
if(h[v] < h[u]) swap(v , u);
v = GetPar(v , h[v] - h[u]);
if(v == u) return v;
for(ll i = LOG - 1 ; i >= 0 ; i --){
if(par[v][i] != par[u][i]){
v = par[v][i];
u = par[u][i];
}
}
return par[v][0];
}
int main()
{
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> m;
E.pb(MP(0 , 0));
for(ll i = 1 ; i <= m ; i ++)
{
ll v , u;
cin >> v >> u;
E.pb(MP(v , u));
if(v == u){
ans[i] = 1;
continue;
}
adj[v].pb(MP(u , i));
adj[u].pb(MP(v , i));
}
for(ll i = 1 ; i <= n ; i ++)
if(!mark[i])
DFS1(i);
cin >> q;
while(q --)
{
ll v , u , w;
cin >> v >> u;
w = LCA(v , u);
dp[v][0] ++;
dp[u][1] ++;
dp[w][0] --;
dp[w][1] --;
}
fill(mark , mark + n + 1 , 0);
for(ll i = 1 ; i <= n ; i ++)
if(!mark[i])
DFS2(i);
for(ll i = 1 ; i <= m ; i ++)
{
auto[v , u] = E[i];
if(ans[i] == 1) { cout << "B"; continue; }
if((h[v] > h[u] && be[v] < h[v]) || (h[u] > h[v] && be[u] < h[u])) { cout << "B"; continue; }
if(h[v] > h[u])
{
if(ans[i] == 2)
cout << "R";
else
cout << "L";
}
else
{
if(ans[i] == 2)
cout << "L";
else
cout << "R";
}
}
return 0;
}
/*!
ahkh
*/
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
4948 KB |
Output is correct |
2 |
Correct |
3 ms |
4948 KB |
Output is correct |
3 |
Correct |
3 ms |
5296 KB |
Output is correct |
4 |
Correct |
4 ms |
5332 KB |
Output is correct |
5 |
Correct |
3 ms |
5292 KB |
Output is correct |
6 |
Correct |
3 ms |
5204 KB |
Output is correct |
7 |
Correct |
3 ms |
5332 KB |
Output is correct |
8 |
Correct |
3 ms |
5332 KB |
Output is correct |
9 |
Correct |
3 ms |
5204 KB |
Output is correct |
10 |
Correct |
3 ms |
5204 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
4948 KB |
Output is correct |
2 |
Correct |
3 ms |
4948 KB |
Output is correct |
3 |
Correct |
3 ms |
5296 KB |
Output is correct |
4 |
Correct |
4 ms |
5332 KB |
Output is correct |
5 |
Correct |
3 ms |
5292 KB |
Output is correct |
6 |
Correct |
3 ms |
5204 KB |
Output is correct |
7 |
Correct |
3 ms |
5332 KB |
Output is correct |
8 |
Correct |
3 ms |
5332 KB |
Output is correct |
9 |
Correct |
3 ms |
5204 KB |
Output is correct |
10 |
Correct |
3 ms |
5204 KB |
Output is correct |
11 |
Correct |
45 ms |
18628 KB |
Output is correct |
12 |
Correct |
62 ms |
21900 KB |
Output is correct |
13 |
Correct |
90 ms |
26700 KB |
Output is correct |
14 |
Correct |
114 ms |
33364 KB |
Output is correct |
15 |
Correct |
111 ms |
35168 KB |
Output is correct |
16 |
Correct |
100 ms |
34996 KB |
Output is correct |
17 |
Correct |
106 ms |
36544 KB |
Output is correct |
18 |
Correct |
94 ms |
35000 KB |
Output is correct |
19 |
Correct |
103 ms |
37748 KB |
Output is correct |
20 |
Correct |
76 ms |
25228 KB |
Output is correct |
21 |
Correct |
63 ms |
24872 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
4948 KB |
Output is correct |
2 |
Correct |
3 ms |
4948 KB |
Output is correct |
3 |
Correct |
3 ms |
5296 KB |
Output is correct |
4 |
Correct |
4 ms |
5332 KB |
Output is correct |
5 |
Correct |
3 ms |
5292 KB |
Output is correct |
6 |
Correct |
3 ms |
5204 KB |
Output is correct |
7 |
Correct |
3 ms |
5332 KB |
Output is correct |
8 |
Correct |
3 ms |
5332 KB |
Output is correct |
9 |
Correct |
3 ms |
5204 KB |
Output is correct |
10 |
Correct |
3 ms |
5204 KB |
Output is correct |
11 |
Correct |
45 ms |
18628 KB |
Output is correct |
12 |
Correct |
62 ms |
21900 KB |
Output is correct |
13 |
Correct |
90 ms |
26700 KB |
Output is correct |
14 |
Correct |
114 ms |
33364 KB |
Output is correct |
15 |
Correct |
111 ms |
35168 KB |
Output is correct |
16 |
Correct |
100 ms |
34996 KB |
Output is correct |
17 |
Correct |
106 ms |
36544 KB |
Output is correct |
18 |
Correct |
94 ms |
35000 KB |
Output is correct |
19 |
Correct |
103 ms |
37748 KB |
Output is correct |
20 |
Correct |
76 ms |
25228 KB |
Output is correct |
21 |
Correct |
63 ms |
24872 KB |
Output is correct |
22 |
Correct |
216 ms |
37780 KB |
Output is correct |
23 |
Correct |
183 ms |
36312 KB |
Output is correct |
24 |
Correct |
149 ms |
36064 KB |
Output is correct |
25 |
Correct |
205 ms |
40760 KB |
Output is correct |
26 |
Correct |
199 ms |
37336 KB |
Output is correct |
27 |
Correct |
165 ms |
36244 KB |
Output is correct |
28 |
Correct |
37 ms |
12036 KB |
Output is correct |
29 |
Correct |
130 ms |
25976 KB |
Output is correct |
30 |
Correct |
148 ms |
26052 KB |
Output is correct |
31 |
Correct |
130 ms |
26428 KB |
Output is correct |
32 |
Correct |
151 ms |
30904 KB |
Output is correct |