I Tried To Speedrun LeetCode MEDIUMS

In the last speedrun, I gave myself an hour to do as many LeetCode easies as possible... and took out 53. In this one, I still have an hour, but now the goal is to do at least 20 mediums. Can it be done?

Music

This Is For You (Prod. by Lukrembo)

Dreams by Bensound

Local Forecast - Slower by Kevin MacLeod
License: [yt dislikes this link, removed]

Timestamps
0:00:00 Intro
0:01:06 Speedrun
1:00:07 Conclusion

[johnvanschultz]

Colin successfully solved the first question while I was still trying to understand what it was asking

[CostaKazistov]

Watching Codeforces red smashing LeetCode mediums, going "is that it?"
Just awesome!

[andrewchen]

That's crazy... Thank you for this video!

[AnkitRaj-zmme]

Leetcode after seeing Grandmaster coders :- please leave me, don't destroy me😭😭

[akidas]

Lol imagine solving an interviewers problem in 2mins, watching their mind explode and then spend rest of the time explaining it to the poor dude.
You should do interviews just to mess with these arrogant fools who want us normies to solve 2 mediums in 30mins while interrupting every 30secs.

[arunm]

Thanks Colin!
I coded along with you and solved the 22 problems in 1 day.
your coding is a black magic indeed!

[teja]

This is honestly making me cry, this dood is amazing

[labidyramzi]

Keep the good work up man !! We want more videos on you solving problems on leetcode

[IllIIIIIIllll]

8:03 the realisation, every coders can relate this 😂

[Inndjkaawed]

The first question took me two days to solve

[TheUmangTarang]

Really cool seeing you implement solutions so fast, this can be great guide on how to code elegantly. I generally can think of the solution but may not write a smooth code for it, seeing this can be helpful. It may be difficult to do but could you create a video on how to write elegant solutions? I know a lot of it can be just practice but if there are some ideas one should keep in mind when coding that can help learning to write good solutions faster can be great.

Maybe taking a look at leetcode's least upvoted accepted submissions and compare them with most upvoted ones can give you some ideas. There are dudes which literally solve LC hard in like 15 lines of code whereas I write 50 lines lol

[manishbolbanda]

amazing video. Thanks for your efforts Colin.

[Daman]

the first solution itself blew my mind

[UNMEASURED]

That's the video I needed. Thanks

[trishdz]

Which platform is better? LeetCode or Hackerrank?

[shivam-codes]

Pls make CF div2 post contest videos
As most of the coders are div2
Thank you 🙌🏻

[akashverma]

Even genius can get confused in LinkedList problems without Pen and Paper.

[oliverheber]

For the third question, find the cumulative sum of the binary tree's deepest leaves, doesn't his algorithm search only the left-most and only the right-most leaf? What if on the left side of the tree the final node had a right leaf and visa versa for the right side. It is a binary tree not a binary search tree so the positioning of the nodes can be in any order?

[titusandronikus]

Many questions either implied or explicitly asked for in-place, const memory solutions, but you just ignored that. It was kind of disappointing. The overall speed is still ridiculously impressive, though!

[jollyjoker]

IMO you overly complicated the skyline one (13:30). Everything can be boosted to min(highest in row, highest in column) and those are easy to calculate.
const rotate = grid => grid.map((_, xidx) => grid.map(arr => arr[xidx]))
const maxes = grid => grid.map(arr => Math.max(...arr))
const sum = arr => arr.reduce((a, b) => a + b)

const maxIncreaseKeepingSkyline = grid => {
const maxRows = maxes(grid)
const maxCols = maxes(rotate(grid))
return sum(grid.map(
(arr, x) => sum(arr.map(
(n, y) => Math.min(maxRows[x], maxCols[y]) - n
))
))
}
(Yeah, I'm a programmer but not a competitive one as you can se from the code :) )