oj.uz

Submission #47792

# Submission time Handle Problem Language Result Execution time Memory
47792 2018-05-07T09:09:55 Z Extazy One-Way Streets (CEOI17_oneway) C++17
100 / 100
 337 ms 55764 KB 
#include <bits/stdc++.h>
#define endl '\n'
#define time lkahgkljahkgjkghajahkjg

using namespace std;

const int N = 100007;
const int LOG = 17;

struct edge {
  int to,idx,from_which,to_which;
  
  edge(){}
  edge(int a, int b, int c, int d): to(a), idx(b), from_which(c), to_which(d) {}
};

int n,m;
pair < int, int > e[N];
vector < pair < int, int > > v[N];
vector < edge > k[N];
bool is_bridge[N];
int parent[N],time[N],current_time,low[N];
bool used[N];
int comp[N];
int components_count;
int level[N],jump[N][LOG];
int cntu[N],cntd[N];
int p;
char answer[N];

void dfs1(int node) {
  used[node]=true;
  low[node]=time[node]=++current_time;
  
  int i;

  for(i=0;i<(int)(v[node].size());i++) if(v[node][i].first!=parent[node]) {
    if(!used[v[node][i].first]) {
      parent[v[node][i].first]=node;
      dfs1(v[node][i].first);
      if(low[v[node][i].first]>time[node]) is_bridge[v[node][i].second]=true;
      low[node]=min(low[node],low[v[node][i].first]);
    }
    else {
      low[node]=min(low[node],time[v[node][i].first]);
    }
  }
}

void dfs2(int node, int where) {
  used[node]=true;
  comp[node]=where;

  int i;

  for(i=0;i<(int)(v[node].size());i++) if(!used[v[node][i].first] && !is_bridge[v[node][i].second]) {
    dfs2(v[node][i].first,where);
  }
}

void dfs3(int node) {
  used[node]=true;

  int i;

  for(i=0;i<(int)(k[node].size());i++) if(!used[k[node][i].to]) {
    parent[k[node][i].to]=node;
    level[k[node][i].to]=level[node]+1;
    dfs3(k[node][i].to);
  }
}

void walk_up(int &node, int lvl) {
  for(int i=16;level[node]>lvl;i--) if(level[jump[node][i]]>=lvl) node=jump[node][i];
}

int get_lca(int a, int b) {
  walk_up(a,level[b]);
  walk_up(b,level[a]);

  if(a==b) return a;

  for(int i=16;i>=0;i--) if(jump[a][i]!=jump[b][i]) {
    a=jump[a][i];
    b=jump[b][i];
  }

  return parent[a];
}

void dfs4(int node) {
  used[node]=true;

  int i,to,idx;

  for(i=0;i<(int)(k[node].size());i++) {
    to=k[node][i].to;
    idx=k[node][i].idx;

    if(used[to]) continue;

    dfs4(to);

    cntu[node]+=cntu[to];
    cntd[node]+=cntd[to];

    if(cntu[to]) {
      if(e[idx]==make_pair(k[node][i].to_which,k[node][i].from_which)) {
        answer[idx]='R';
      }
      else {
        answer[idx]='L';
      }
    }
    else if(cntd[to]) {
      if(e[idx]==make_pair(k[node][i].from_which,k[node][i].to_which)) {
        answer[idx]='R';
      }
      else {
        answer[idx]='L';
      }
    }
  }
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int i,j,x,y,lca;

  scanf("%d %d", &n, &m);
  for(i=1;i<=m;i++) {
    scanf("%d %d", &e[i].first, &e[i].second);
    v[e[i].first].push_back(make_pair(e[i].second,i));
    v[e[i].second].push_back(make_pair(e[i].first,i));
    answer[i]='B';
  }

  for(i=1;i<=n;i++) if(!used[i]) {
    dfs1(i);
  }

  fill(used+1,used+1+n,false);
  for(i=1;i<=n;i++) if(!used[i]) {
    dfs2(i,++components_count);
  }

  for(i=1;i<=m;i++) {
    if(is_bridge[i]) {
      k[comp[e[i].first]].push_back(edge(comp[e[i].second],i,e[i].first,e[i].second));
      k[comp[e[i].second]].push_back(edge(comp[e[i].first],i,e[i].second,e[i].first));
    }
  }

  fill(used+1,used+1+n,false);
  for(i=1;i<=n;i++) if(!used[i]) {
    parent[i]=0;
    level[i]=1;
    dfs3(i);
  }

  for(i=1;i<=n;i++) {
    jump[i][0]=parent[i];
  }
  for(j=1;j<17;j++) {
    for(i=1;i<=n;i++) {
      jump[i][j]=jump[jump[i][j-1]][j-1];
    }
  }

  scanf("%d", &p);
  for(i=1;i<=p;i++) {
    scanf("%d %d", &x, &y);
    
    if(comp[x]==comp[y]) continue;

    lca=get_lca(comp[x],comp[y]);

    ++cntu[comp[x]];
    ++cntd[comp[y]];
    --cntu[lca];
    --cntd[lca];
  }

  fill(used+1,used+1+n,false);
  for(i=1;i<=components_count;i++) if(!used[i]) {
    dfs4(i);
  }

  for(i=1;i<=m;i++) {
    printf("%c", answer[i]);
  }

  printf("\n");

  return 0;
}

Compilation message

oneway.cpp: In function 'int main()':
oneway.cpp:131:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &n, &m);
   ~~~~~^~~~~~~~~~~~~~~~~
oneway.cpp:133:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &e[i].first, &e[i].second);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
oneway.cpp:171:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &p);
   ~~~~~^~~~~~~~~~
oneway.cpp:173:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &x, &y);
     ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 5112 KB Output is correct
2 Correct 5 ms 5112 KB Output is correct
3 Correct 6 ms 5292 KB Output is correct
4 Correct 7 ms 5524 KB Output is correct
5 Correct 8 ms 5524 KB Output is correct
6 Correct 6 ms 5524 KB Output is correct
7 Correct 7 ms 5524 KB Output is correct
8 Correct 6 ms 5588 KB Output is correct
9 Correct 6 ms 5588 KB Output is correct
10 Correct 6 ms 5644 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 5112 KB Output is correct
2 Correct 5 ms 5112 KB Output is correct
3 Correct 6 ms 5292 KB Output is correct
4 Correct 7 ms 5524 KB Output is correct
5 Correct 8 ms 5524 KB Output is correct
6 Correct 6 ms 5524 KB Output is correct
7 Correct 7 ms 5524 KB Output is correct
8 Correct 6 ms 5588 KB Output is correct
9 Correct 6 ms 5588 KB Output is correct
10 Correct 6 ms 5644 KB Output is correct
11 Correct 82 ms 12452 KB Output is correct
12 Correct 78 ms 15180 KB Output is correct
13 Correct 99 ms 18900 KB Output is correct
14 Correct 123 ms 23700 KB Output is correct
15 Correct 131 ms 26192 KB Output is correct
16 Correct 160 ms 31672 KB Output is correct
17 Correct 157 ms 33904 KB Output is correct
18 Correct 169 ms 33948 KB Output is correct
19 Correct 159 ms 37124 KB Output is correct
20 Correct 107 ms 37124 KB Output is correct
21 Correct 75 ms 37124 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 5112 KB Output is correct
2 Correct 5 ms 5112 KB Output is correct
3 Correct 6 ms 5292 KB Output is correct
4 Correct 7 ms 5524 KB Output is correct
5 Correct 8 ms 5524 KB Output is correct
6 Correct 6 ms 5524 KB Output is correct
7 Correct 7 ms 5524 KB Output is correct
8 Correct 6 ms 5588 KB Output is correct
9 Correct 6 ms 5588 KB Output is correct
10 Correct 6 ms 5644 KB Output is correct
11 Correct 82 ms 12452 KB Output is correct
12 Correct 78 ms 15180 KB Output is correct
13 Correct 99 ms 18900 KB Output is correct
14 Correct 123 ms 23700 KB Output is correct
15 Correct 131 ms 26192 KB Output is correct
16 Correct 160 ms 31672 KB Output is correct
17 Correct 157 ms 33904 KB Output is correct
18 Correct 169 ms 33948 KB Output is correct
19 Correct 159 ms 37124 KB Output is correct
20 Correct 107 ms 37124 KB Output is correct
21 Correct 75 ms 37124 KB Output is correct
22 Correct 269 ms 40792 KB Output is correct
23 Correct 254 ms 41944 KB Output is correct
24 Correct 284 ms 44652 KB Output is correct
25 Correct 337 ms 50156 KB Output is correct
26 Correct 247 ms 50156 KB Output is correct
27 Correct 249 ms 51416 KB Output is correct
28 Correct 57 ms 51416 KB Output is correct
29 Correct 118 ms 51416 KB Output is correct
30 Correct 117 ms 51416 KB Output is correct
31 Correct 126 ms 51416 KB Output is correct
32 Correct 178 ms 55764 KB Output is correct