oj.uz

Submission #56077

# Submission time Handle Problem Language Result Execution time Memory
56077 2018-07-09T21:01:05 Z IvanC One-Way Streets (CEOI17_oneway) C++17
100 / 100
 580 ms 28200 KB 
#include <bits/stdc++.h>
using namespace std;
 
typedef pair<int,int> ii;
 
const int MAXN = 1e5 + 10;
const int BUCKET = 330; 

vector<int> grafo[MAXN],tree[MAXN],procurar1[MAXN],procurar2[MAXN];
vector<ii> pares;
map<ii,int> cjt;
int low[MAXN],num[MAXN],jafoi[MAXN],dfsNum,compId[MAXN],compAtual;
int e1[MAXN],e2[MAXN],e3[MAXN],e4[MAXN],ehponte[MAXN];
int tipo1[MAXN],tipo2[MAXN],altura[MAXN],liga[MAXN],pai[MAXN],superpai[MAXN],q1[MAXN],q2[MAXN],N,M,K;
 
void dfs_tarjan(int v,int aresta){
  num[v] = ++dfsNum;
  low[v] = dfsNum;
  for(int i : grafo[v]){
    if(i == aresta) continue;
    int u = (e1[i] != v) ? (e1[i]) : (e2[i]);
    if(num[u] == 0){
      dfs_tarjan(u,i);
      if(low[u] > num[v]) ehponte[i] = 1;
      low[v] = min(low[v],low[u]);
    }
    else{
      low[v] = min(low[v],num[u]);
    }
  }
}
 
void dfs_bridge(int v,int aresta){
  jafoi[v] = 1;
  for(int i : grafo[v]){
    if(i == aresta) continue;
    int u = (e1[i] != v) ? (e1[i]) : (e2[i]);
    if(jafoi[u]) continue;
    if(ehponte[i]){
      compAtual++;
      compId[u] = compAtual;
      dfs_bridge(u,i);
    }
    else{
      compId[u] = compId[v];
      dfs_bridge(u,i);
    }
  }
}
 
void dfs1(int v,int p){
  //printf("DFS\n");
  for(int i : tree[v]){
    int u = (e3[i] != v) ? (e3[i]) : (e4[i]);
    if(u == p) continue;
    pai[u] = v;
    liga[u] = i;
    altura[u] = altura[v] + 1;
    dfs1(u,v);
  }
}

void dfs2(int v,int p,int sp){
  superpai[v] = sp;
  if((altura[v] - 1) % BUCKET == 0) sp = v;
  for(int i : tree[v]){
    int u = (e3[i] != v) ? (e3[i]) : (e4[i]);
    if(u == p) continue;
    dfs2(u,v,sp);
  }
}
 
void LCA(int u,int v){
  while(superpai[u] != superpai[v]){
    if(altura[u] >= altura[v]){
      q1[u]++;
      u = superpai[u];
    }
    else{
      q2[v]++;
      v = superpai[v];
    }
  }
  while(u != v){
    //printf("U %d V %d\n",u,v);
    if(altura[u] >= altura[v]){
      //printf("Tipo1 %d %d\n",u,liga[u]);
      tipo1[liga[u]]++;
      u = pai[u];
    }
    else{
      //printf("Tipo2 %d %d\n",v,liga[v]);
      tipo2[liga[v]]++;
      v = pai[v];
    }
  }
}

void processa(int v){
  int d1 = q1[v],d2 = q2[v],alvo = superpai[v];
  while(v != alvo){
    tipo1[liga[v]] += d1;
    tipo2[liga[v]] += d2;
    v = pai[v];
  }
}

int main(){
  scanf("%d %d",&N,&M);
  for(int i = 1;i<=M;i++){
    scanf("%d %d",&e1[i],&e2[i]);
    grafo[e1[i]].push_back(i);
    grafo[e2[i]].push_back(i);
  }
  scanf("%d",&K);
  for(int i = 1;i<=K;i++){
    int u,v;
    scanf("%d %d",&u,&v);
    pares.push_back(ii(u,v));
  }
  for(int i = 1;i<=N;i++){
    if(num[i] != 0) continue;
    dfs_tarjan(i,-1);
    compAtual++;
    compId[i] = compAtual;
    dfs_bridge(i,-1);
  }
  //printf("Pontes\n");
  for(int i = 1;i<=M;i++){
    if(!ehponte[i]) continue;
    e3[i] = compId[e1[i]];
    e4[i] = compId[e2[i]];
    //printf("%d %d %d %d\n",e1[i],e2[i],e3[i],e4[i]);
    tree[e3[i]].push_back(i);
    tree[e4[i]].push_back(i);
  }
 
  for(int  i = 1;i <= compAtual;i++){
    if(altura[i] != 0) continue;
    //printf("DFS1 %d\n",i);
    altura[i] = 1;
    dfs1(i,-1);
    dfs2(i,-1,i);
    //printf("Foi\n");
  }
 
  for(ii davez : pares){
    int u = compId[davez.first],v = compId[davez.second];
    if(u == v) continue;
    LCA(u,v);
  }
 
  for(int i = 1;i<=compAtual;i++) processa(i); 

  for(int i = 1;i<=M;i++){
    if(ehponte[i] == 0){
      printf("B");
    }
    else if(tipo1[i]){
      if(altura[e3[i]] > altura[e4[i]]) printf("R");
      else printf("L");
    }
    else if(tipo2[i]){
      if(altura[e3[i]] < altura[e4[i]]) printf("R");
      else printf("L");
    }
    else{
      printf("B");
    }
  }
  printf("\n");
  return 0;
}

Compilation message

oneway.cpp: In function 'int main()':
oneway.cpp:109:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d",&N,&M);
   ~~~~~^~~~~~~~~~~~~~~
oneway.cpp:111:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d",&e1[i],&e2[i]);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~
oneway.cpp:115:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&K);
   ~~~~~^~~~~~~~~
oneway.cpp:118:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d",&u,&v);
     ~~~~~^~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 9720 KB Output is correct
2 Correct 9 ms 9828 KB Output is correct
3 Correct 10 ms 10008 KB Output is correct
4 Correct 10 ms 10072 KB Output is correct
5 Correct 10 ms 10120 KB Output is correct
6 Correct 9 ms 10120 KB Output is correct
7 Correct 15 ms 10144 KB Output is correct
8 Correct 14 ms 10144 KB Output is correct
9 Correct 12 ms 10144 KB Output is correct
10 Correct 12 ms 10144 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 9720 KB Output is correct
2 Correct 9 ms 9828 KB Output is correct
3 Correct 10 ms 10008 KB Output is correct
4 Correct 10 ms 10072 KB Output is correct
5 Correct 10 ms 10120 KB Output is correct
6 Correct 9 ms 10120 KB Output is correct
7 Correct 15 ms 10144 KB Output is correct
8 Correct 14 ms 10144 KB Output is correct
9 Correct 12 ms 10144 KB Output is correct
10 Correct 12 ms 10144 KB Output is correct
11 Correct 116 ms 14092 KB Output is correct
12 Correct 76 ms 16804 KB Output is correct
13 Correct 156 ms 18224 KB Output is correct
14 Correct 119 ms 20272 KB Output is correct
15 Correct 125 ms 20780 KB Output is correct
16 Correct 133 ms 22460 KB Output is correct
17 Correct 177 ms 24312 KB Output is correct
18 Correct 144 ms 24312 KB Output is correct
19 Correct 212 ms 25404 KB Output is correct
20 Correct 79 ms 25404 KB Output is correct
21 Correct 98 ms 25404 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 9720 KB Output is correct
2 Correct 9 ms 9828 KB Output is correct
3 Correct 10 ms 10008 KB Output is correct
4 Correct 10 ms 10072 KB Output is correct
5 Correct 10 ms 10120 KB Output is correct
6 Correct 9 ms 10120 KB Output is correct
7 Correct 15 ms 10144 KB Output is correct
8 Correct 14 ms 10144 KB Output is correct
9 Correct 12 ms 10144 KB Output is correct
10 Correct 12 ms 10144 KB Output is correct
11 Correct 116 ms 14092 KB Output is correct
12 Correct 76 ms 16804 KB Output is correct
13 Correct 156 ms 18224 KB Output is correct
14 Correct 119 ms 20272 KB Output is correct
15 Correct 125 ms 20780 KB Output is correct
16 Correct 133 ms 22460 KB Output is correct
17 Correct 177 ms 24312 KB Output is correct
18 Correct 144 ms 24312 KB Output is correct
19 Correct 212 ms 25404 KB Output is correct
20 Correct 79 ms 25404 KB Output is correct
21 Correct 98 ms 25404 KB Output is correct
22 Correct 425 ms 25404 KB Output is correct
23 Correct 580 ms 25404 KB Output is correct
24 Correct 191 ms 25404 KB Output is correct
25 Correct 416 ms 28200 KB Output is correct
26 Correct 407 ms 28200 KB Output is correct
27 Correct 382 ms 28200 KB Output is correct
28 Correct 73 ms 28200 KB Output is correct
29 Correct 101 ms 28200 KB Output is correct
30 Correct 129 ms 28200 KB Output is correct
31 Correct 107 ms 28200 KB Output is correct
32 Correct 229 ms 28200 KB Output is correct