Help me!
Difference between en8 and en9, changed 2 character(s)
Last contest,I failed system test on D,that I didn't become an IGM.↵
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But I don't know why my D failed system test,I submitted the same code $3$ times today,they all get Accepted.See [submission:72380842] [submission:72380904] [submission:72381047]↵
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I think it's the problem of randomized integers,but I don't know why.Please help me!↵
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Here's my solution to D:↵
    Let's Maintain candidate roots,at the beginning,every vertex is a candidate root.In each query,we randomly choose two candidate roots that are not adjacent ansd not equal.Let's denote them $x,y$,then we ask $x,y's$ lca,denote it $w$，then for every $w$'s subtree that contains $x$ or $y$,all of the vertex in it can be removed from candidate root.It can be shown that in each query,we remove at least two candidate roots.All the vertices left form a subtree of the original tree.There's a special case on $n=2$,just ask these two vertices.↵
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Here's my submission:[submission:72324004]↵
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Sorry for my poor English.↵

History

 
 
 
 
Revisions
 
 
  Rev. Lang. By When Δ Comment
en9 English endless-chase 2020-03-04 06:12:41 2 Tiny change: 'djacent ans not equal' -> 'djacent and not equal'
en8 English endless-chase 2020-03-04 05:30:26 0 (published)
en7 English endless-chase 2020-03-04 05:30:10 2 Tiny change: 'e ask $x,y$'s lca,denot' -> 'e ask $x,y's$ lca,denot'
en6 English endless-chase 2020-03-04 05:29:37 4
en5 English endless-chase 2020-03-04 05:27:48 74
en4 English endless-chase 2020-03-04 05:24:52 2 Tiny change: '2381047]\nI think ' -> '2381047]\n\nI think '
en3 English endless-chase 2020-03-04 05:24:14 16
en2 English endless-chase 2020-03-04 05:22:18 6
en1 English endless-chase 2020-03-04 05:20:19 912 Initial revision (saved to drafts)