Hi everyone, so I found this problem today, and it seems like a really obvious bipartite matching, but I've been getting TLE in it. Is there some faster way to solve it?
Hi everyone, so I found this problem today, and it seems like a really obvious bipartite matching, but I've been getting TLE in it. Is there some faster way to solve it?
O(VE) bipartite matching algorithm obviously gets TLE on dense graph with such limits. I think solution which runs in O(sqrt(v) * E) will pass. For example you can use "Hopcroft–Karp algorithm".
Sorry, forgot to say I used Hopcroft-Karp.
Strange... Show your code, maybe i can help. Solution with O(N ^ 2.376) exists, but i think Hopcroft-Karp must pass.
Here it is: http://pastebin.com/3RH9u4SN
Your algorithm works in O(VE) time and it isn't Hopcroft-Karp. Just try this testcase: 500 500
2 2 2 2 2 ... (500 times)
2 2 2 2 2 ... (500 times)
Copy this a few times and then add "0 0". Your algorithm will work more then 5 seconds (and will get TLE).
Thanks, I found the mistake, I was using the || operator instead of |= when updating the variable change. With this change it still isn't Hopcroft karp because i'm not taking shortest paths, but that only makes it a bit slower.
Dinnic works here, my solution accepted in 4.86 seconds.