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  # 2-EDGE CONNECTED GRAPH
  
   2 2-edge connected graph means the graph is always connected if we remove any edge of that graph. For checking a graph is a two-edge connected graph , we just need to check whether for every sub-tree of the graph there should be an edge going from that sub-tree to outside vertex and that vertex is already visited.This can be solved by using DFS and in linear time. PSUEDOCODE : The below code returns the minimum value of the arrival time of the back-edge that the sub-tree is connected with.  time=0; 2edgeconnected(v) { visited[v]=1; arr[v]=time++; int xyz=arr[v]; for all w adjecent to v do { if(!visited[w]) xyz=min(xyz,2edgeconnected(w)); else xyz=min(xyz,arr[w]); } if(xyz==arr[v]) abort //graph is not two-edge connected. return xyz; } asked 03 Jul '14, 12:06 2★trek 327●4●12●18 accept rate: 0%
  
   0 nice one!! answered 03 Jul '14, 16:04 4★suryanit 11●1●3●4 accept rate: 0%
   0 Equality will hold for the root node, u need to take care of that case answered 06 Dec '17, 23:21 1 accept rate: 0%
   0 Equality will hold for the root node, u need to take care of that case answered 06 Dec '17, 23:22 1 accept rate: 0%
   0 Useful one... But same problem can be solved by following two checks: Graph is connected (Simple DFS) Graph does not contains a bridge. (Another DFS) Read more about bride finding here. If both of above two conditions hold true, graph is 2-edge connected. Time Complexity of this Solution: O(N+M) Above two DFS can also be combined into a single DFS to improve time complexity. Anyways, Nice editorial. answered 06 Dec '17, 23:52 3.6k●13●51 accept rate: 24%
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  question asked: 03 Jul '14, 12:06
  
  question was seen: 3,594 times
  
  last updated: 06 Dec '17, 23:52
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