i consider the 2 first, so there is a circle whose vertices were 2.Then i try to use the lest 0, so i insert double 1 between 2 and 2, finally i insert 0 into the circle.

i can't figure out what's wrong with mycode,help!

C(n + k — 1, k — 1) for putting n same balls into k different buckets(allow none)，mine

gosh, I BFS the whole matrix from every 'E' and did time-wasting things to ensure the
shortest distance, I didn't even think about it

BFS got TLE in D, anyone help?

Actually, there are only 96 participants AK

respect! my dp transform fuction just couldn't handle the case where D is 0!

5 TCS, too

the 3rd sample of div2 C really frustrated me, anyone help?