What is the error in the first logic? Related to Edu119 Problem E
Difference between en1 and en2, changed 195 character(s)
Problem: https://codeforces.net/contest/1620/problem/E↵
↵
I was trying to apply some *dsu-like* logic in Problem E, when they asked for replacement of every x$x$ with y$y$ in the array, but it gave me `WA on test 4`.↵
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The idea which I used during the contest:↵
↵
```↵
from = replacement[x], to = replacement[y]↵
while(replacement[to] != to) to = replacement[to];↵
replacement[from] = to;↵
```↵
↵
And, the idea which gave AC after the contest,↵
↵
```↵
replacement[x] = replacement[y]↵
```↵
↵
I know that the latter one is clever and more sleek, but why the former one fails? Can anyone please suggest a counter-case for it?↵
↵
Except for these idea, the rest of code was exact same!↵
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Submission 1 (with first logic): https://codeforces.net/contest/1620/submission/139872871  ↵
Submission 2 (with second logic): https://codeforces.net/contest/1620/submission/139872969

History

 
 
 
 
Revisions
 
 
  Rev. Lang. By When Δ Comment
en2 English the_drunken_knight 2021-12-19 12:15:29 195 Tiny change: '39872871\nSubmissi' -> '39872871\n\nSubmissi'
en1 English the_drunken_knight 2021-12-18 21:46:32 738 Initial revision (published)