I was trying to apply some dsu-like logic in Problem E, when they asked for replacement of every $$$x$$$ with $$$y$$$ in the array, but it gave me
WA on test 4.
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!
Submission 1 (with first logic): https://codeforces.com/contest/1620/submission/139872871
Submission 2 (with second logic): https://codeforces.com/contest/1620/submission/139872969