fork download
copy 
  1. #include <bits/stdc++.h>
  2. using namespace std;
  3.  
  4. typedef long long int ll;
  5. typedef vector<int> vi;
  6. typedef pair<int,int> ii;
  7. typedef vector<ii> vii;
  8. #define F(i,a,b) for(int i = (int)(a); i <= (int)(b); i++)
  9. #define RF(i,a,b) for(int i = (int)(a); i >= (int)(b); i--)
  10. #define MOD 1000000007
  11. #define DFS_WHITE -1
  12. #define DFS_BLACK 1
  13.  
  14. class Graph
  15. {
  16. private:
  17.     int V;
  18.     vector<vii> AdjList;
  19.     void dfs_util(int v, int dfs_num[]);
  20. public:
  21.     Graph(int V);
  22.     void addEdge(int u, int v, int wt);
  23.     void dfs();
  24. };
  25.  
  26. Graph::Graph(int V)
  27. {
  28.     this->V = V;
  29.     AdjList.assign(V, vii());
  30. }
  31.  
  32. void Graph::addEdge(int u, int v, int wt)
  33. {
  34.     AdjList[u].push_back(ii(v,wt));
  35. }
  36.  
  37. void Graph::dfs_util(int u, int dfs_num[])
  38. {
  39.     printf("Visiting  %d\n",u);
  40.     dfs_num[u] = DFS_BLACK;
  41.     for(int j = 0; j < (int)AdjList[u].size(); j++)
  42.     {
  43.         ii v = AdjList[u][j];
  44.         if(dfs_num[v.first] == DFS_WHITE)
  45.             dfs_util(v.first, dfs_num);
  46.     }
  47. }
  48. void Graph::dfs()
  49. {
  50.     int dfs_num[V];
  51.     F(i,0,V-1) dfs_num[i] = -1;
  52.     F(i,0,V-1)
  53.     {
  54.         if(dfs_num[i] == DFS_WHITE)
  55.             dfs_util(i,dfs_num);
  56.     }
  57.  
  58. }
  59. int main()
  60. {
  61.     int N,M,u,v;
  62.     scanf("%d%d",&N,&M);
  63.     Graph G(N);
  64.     F(i,0,M-1)
  65.     {
  66.         scanf("%d%d",&u,&v);
  67.         G.addEdge(u,v,0);
  68.     }
  69.     G.dfs();
  70.     return 0;
  71. }
  72.  
  73.  
Success #stdin #stdout 0s 3464KB
comments (?)
stdin
copy 
3 3
0 1
1 0
1 2
stdout
copy 
Visiting  0
Visiting  1
Visiting  2
https://ideone.com/mzO53Y
language:
C++14 (gcc 8.3)
created:
8 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!