Remove Max Number of Edges to Keep Graph Fully Traversable - Leetcode 1579 - Python

Solving Leetcode 1579 - Remove Max Number of Edges to Keep Graph Fully Traversable, todays daily leetcode problem on April 29.

0:00 - Read the problem
2:00 - Drawing Explanation
13:00 - Coding Explanation

leetcode 1579

#neetcode #leetcode #python

[NeetCodeIO]

Looking forward to next month btw - hopefully not a Hard problem every f*cking day xD

[def__init]

15:58 "we want to increment count by 1 pretty much every time" -- obvs this is hyperbole, but for anyone actually curious you do still need to check the union result of type 3 edges for alice and bob, so if you don't like bitwise OR operator you could do:
cnt += max(alice.union(src, dst), bob.union(src, dst)) for same effect, or have your union return True/False, etc

[aadil]

9:56 You misspoke here. It's not the green edges that are traversable for both Alice and Bob but the blue one. Leaving the comment so other people don't get confused.

[aniketmahangare]

Thanks man. I was able to solve the question on my own this time but it wouldn’t have been possible without your content.

[YouTube_Staff]

I feel you, these union find dailies are brutal, I haven't had to do one in a long while.

[ouchlock]

Thanks. With these hard tasks I often need your clean explanations.

[krateskim]

Neetcode to the rescue, awesome explanation

[hemanth]

you are confused with both green and blue edges throughout the video but no worries i got the point man 👍

[EasterBunnyGaming]

also works with minimum spanning tree approach

[sharathkumar]

please keep uploading hard problems as well. Thank you

[parashararamesh]

Pretty neat solution. Also point to note, it doesnt look like your union find class implements path compression. It only looks like it does union find with rank

[GameFlife]

funny how my algorithm teacher doesnt tell us to code but draw the edge but now when i do leetcode it show up...

[Rancha]

16:09 Solution is not working unless I do bit wise or operation, this does not make any sense. Can anyone explain please ?

[lvisbl__]

I understand why we need to choose edges of type 3 first, but do the order type 3 edges is matter? For example we have 10 type 3 edges, we need to figure which type 3 edges to choose first to maximize the number of type 3 edges chosen.

[BurhanAijaz]

you werent uploading for so many days, everything alright ??

[qulinxao]

class Solution:
def maxNumEdgesToRemove(self, n: int, e: List[List[int]]) -> int:
def h(z):
while
return z
b=[list(range(n+1)), [], []]
for t in range(3):
u=b[t]=b[0][:]
for v, w in ((v, w)for s, v, w in e if t+s==3):
u[v:=h(v)]=(w:=h(w))
u[0]+=(v!=w)
if t and u[0]!=n-1:return -1
return len(e)-2*(n-1)+b[0][0]

[BurhanAijaz]

please code like you usually do, dont write the code before, that way we are more involved

[hypermeero]

Neetcode can you explain Checking Existence of Edge Length Limited Paths problem 🥹, it's 1697 on leetcode