I have the same problem with my code.
Can anyone please help, why my code is giving WA.
Code link : Tf3P1A - Online C++0x Compiler & Debugging Tool - Ideone.com
Can it be the case that the checker function of codechef for this question is incorrect?? @admin
@ankesh18 Both the loop runs till cnt!=m, so total number of operation will be m and hence it will not give TLE. Time complexity of @nmalviya1929 's code is O(T*m).
I got a WA too, and I cannot figure out a case where it would fail,
Can we have this problem rejudged once cases are corrected ? @admin
it took 20 mins for knowing whether our solution for this problem was right or wrong , submitted at 9:30 and got to know the “wrong” verdict at 9:50 with 10 mins left, didn’t expect such carelessness from codechef for this contest.
your solution is wrong. u also have to take care not to assign degree more than D. i see that u haven’t taken care of that. @nmalviya
@nmalviya Try this case 100 10000 1 10
UPD-Sorry Wrong Case…
guys,most of you have made same mistake.you all are printing edges and then checking the condition.
@nmalviya Try this:
1 0 0 1
your output is 1 1.but no. of edges to be printed is 0.
hope this helps.
Yes, I have the same doubt.
Rejudging solutions still doesn’t give us the time we would have got “during” the contest.
Not to mention those 10 minutes of “running” for each supposedly wrong submission.
So many faults while hosting such an important contest is simply not justified.
Did u guys handle the case when m=0 and n=0?? Even I couldn’t figure it out until the contest finished. 
I just don’t know what people at Codechef office are happy about.
Reference: Redirecting...
There servers weren’t ready to take the load of the high submission rate but still they went for the Common Online Test. My team was logged out 9-10 times due to session limit and the submission’s were in Queue for more than 20 minutes. It’s just frustating.
@naksh9619
d and D should be less than equal to n to make a valid bipartite graph.
1 2 1 3 is not valid input.
further m<=n*n condition is also not satisfied in your case.
answer -1 is coming from his code and that’s the correct answer
@tumblehead When n=100 and m=10000,every node of bipartite graph has degree 100, which doesn’t satisfy the condition d<=deg(v)<=D (d=1 & D=10). And @nmalviya1929 's code is giving -1 answer for that, which is correct.
Approach used here is greedy and degree of n nodes is increased one by one. To increase degree of all nodes by one, we need n edges. And condition m<=((2nD)/2) is already checked.
There is a constraint mentioning d>=1