Questions asked by knakul853https://discuss.codechef.com/questions/asked-by/298012/knakul853/?type=rssQuestions asked by <a href="/users/298012/knakul853" >knakul853</a>enMon, 11 Feb 2019 20:52:59 +0530BFS - propertieshttps://discuss.codechef.com/questions/142089/bfs-properties<p>Hi there,<br>
i'm trying to understand the bfs properties(last one) which is described <a href="https://cp-algorithms.com/graph/breadth-first-search.html">here</a></p>
<p>can anyone explain . thanks in advance :)<br>
<strong>Find the shortest path of even length from a source vertex s
to a target vertex t in an unweighted graph: For this, we must construct an auxiliary graph, whose vertices are the state (v,c), where v - the current node, c=0 or c=1 - the current parity. Any edge (a,b) of the original graph in this new column will t<urn into two edges ((u,0),(v,1)) and ((u,1),(v,0)). After that we run a BFS to find the shortest path from the starting vertex (s,0) to the end vertex (t,0).</strong></p>knakul853Sat, 15 Dec 2018 00:38:28 +0530https://discuss.codechef.com/questions/142089/bfs-propertiesbfsEducational contest requesthttps://discuss.codechef.com/questions/145244/educational-contest-request<p>Hi everyone</p>
<p>i would like request Codechef to hold Educational contest like AtCoder organize <a href="https://atcoder.jp/contests/dp/">link </a> .
I think this would be a great idea, helping many of us gaining the basics of topics quickly. Holding them at a every 10 days or so time interval would allow enough time to prepare the contest as well as give contestants time to upsolve the last one.</p>
<p>I hope this is seriously considered!</p>knakul853Mon, 11 Feb 2019 20:52:59 +0530https://discuss.codechef.com/questions/145244/educational-contest-requestrequest