EC_P  Critical Edges
This time I will not bore you with a long and boring sentence. Give a connected graph, you must find all the edges that are critical, in other words you must find the edges which when removed divide the graph.
Input
The first line contains a integer NC (1 ≤ NC ≤ 200), the number of test cases. Then follow NC test cases.
Each case begins with two integers N (1 ≤ N ≤ 700) and M (N1 ≤ M ≤ N * (N1) / 2), the number of nodes and the number of edges respectively. Then follow M lines, each with a pair of integers a b (1 ≤ a, b ≤ N) indicate that between the node a and the node b there is a edge.
Output
For each test case print the list of ways to protect the following format:
Caso # <n>
<t>
<x1> <y2>
<x2> <y2>
...
<xt> <yt>
Where n is the case number (starting from 1), t is the total of critical edges, list elements x_{i} y_{i} indicates, for each line, there is a critical edge between the node x_{i} and node y_{i} (1 ≤ x_{i} <y_{i} ≤ N). In addition, the list should be sorted in nodecreasing order first by x_{i} and then by y_{i}. Also x_{i} < y_{i} must hold.
If there isn't any critical edge print: "Sin bloqueos" (quotes for clarity).
Example
Input:3 5 4 1 2 4 2 2 3 4 5 5 5 1 2 1 3 3 2 3 4 5 4 4 6 1 3 1 4 2 1 3 2 4 2 4 3Output:Caso #1 4 1 2 2 3 2 4 4 5 Caso #2 2 3 4 4 5 Caso #3 Sin bloqueos
hide comments
messier22:
20210519 18:41:13
Take care of the output format. 

dineshbarri:
20210405 10:26:34
Need not check for multiple edges. Just add this step instead inserting directly > bridge.pb({min(u,it),max(u,it)}); 

ashutosh_coder:
20210201 07:29:18
not take another case like if there is n1 edges then simply print edges in sorted order


nadstratosfer:
20210106 02:17:22
Impossible to AC with raw Python in 0.1s and PyPy is disabled for no reason; downvote. 

amit_as_king:
20200709 09:54:19
showing TLE in JAVA even with fast IO Last edit: 20200709 09:55:46 

subhash2000:
20200701 19:02:01
Showing TLE in java while code is O(V+E). Can anyone tell better approach in java 

abu_rifat:
20200411 20:24:06
AC in 1 Go. :) 

luvkumbi:
20200220 19:40:19
Cool....learned to detect bridges in a graph....while inserting bridges in final ans.....see that xi<yi and also print edges in lexographically increasing order. 

jerry_san:
20191208 20:30:16
I am getting runtime error in this question. can someone help me with this 

parsae:
20191030 08:53:23
can anyone give a test case 
Added by:  Eddy Cael 
Date:  20131031 
Time limit:  0.100s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  CCLANG C C++ 4.3.2 CPP CPP14 CPP14CLANG JAVA PYTHON PYTHON3 