Decode String - Leetcode 394 - Python

0:00 - Read the problem
3:45 - Drawing Explanation
12:07 - Coding Explanation

leetcode 394

#decode #string #python
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[gazijarin]

The fact that you appended the string AFTER the pop made the problem so easy. I was shaking my head in horror trying to reverse the string once after appending it.

[TheElementFive]

Very comprehensive problem to practice stacks! Together with asteroid collision and daily temps, one can argue understanding those 3 problems alone are a solid prep for stack problems on interviews.

[Iamnoone]

this was asked in my amazon sde 1 interview somehow i managed t solved it. holy cow!

[ShivangiSingh-wcgk]

Did this myself and came to see the solution. I am so happy to see my progress. Thank you soooo much!!!

[harishsn]

I know you probably hear this a lot but your explanations are so clear and easy to grasp. Thanks a ton for this.

[shubhamshrivastava]

Amazingly explained, was able to implement without even looking at code. Thank you!

[deathbombs]

Great explanation and diagrams!! This is what I got:

The things to decode have this pattern: Coefficient(content)
2 things needed:coefficient, and content

My approach using stack was adding just the {}, and tracking the indexes for substring
, but I like your approach is cleaner by adding everything to stack.
General approach:
for all chars in string
if stack is Empty:
if isDigit: calculate the numerical part/coefficient,
if (, add to stack, save startindex
if is character, add to string builder
if stack is not empty:
add everything
if is ), remove from stack
if stack is empty, recursively call helper(s.substring(startIndex+1, endIndex)

[susmi]

You explain these problems so well! can you please do a video on the problem " Guess the word" ?

[arghya_]

One of the best solution availabe on YT. Great work sir. Huge fan of the way you break tough and/or complex problems into simpler versions!!😍😍

[cherylto]

Love your videos, the clearest explainations I've come across among all the other ones ... Keep it up!

[amogchandrashekar]

You make things feel so easy!
Thank you so much 😀

[AnupBhatt]

First coding channel on Youtube that I put the bell icon to receive all updates for !!

[LeetCodeSimplified]

According to LeetCode premium, the time complexity of this solution is actually O(maxK^countK * n), where maxK is the maximum value of k, countK is the count of nested k values and n is the maximum length of the encoded string. Example, for s = 20[a10[bc]], maxK is 20, countK is 2 as there are 2 nested k values (20 and 10). Also, there are 2 encoded strings a and bc with the maximum length of the encoded string n as 2.

[kashishshukla]

Best explanation man! TYSM for your efforts.

[chenhaibin]

Great clear explanation as always. thanks

[brandenimmerzeel]

Thanks, i ended up solving this with recursion on my first attempt. I used this video to learn how to apply stacks to the problem. Thank you.

[october]

wow usually I feel a bit anxious when not able to come up with a soln, I have been watching ur few vids! explanations r crisp and easy to understand, I even like it's in python while I code in cpp lol

[begenchorazgeldiyev]

I don't know why I am still using java. I came up with the same solution with a stack but it is at least twice longer thanks to java. This is so easy to read and comprehend.

[pif]

Great video! Thanks! This problem showed me stacks are amazing for accruing and backtracking in an organic way!

[atulkumar-bbvi]

Explanation put very simple way, thanks for this!