Palindromic Substrings - Leetcode 647 - Python

0:00 - Read the problem
2:54 - Drawing Explanation
11:25 - Coding Explanation

leetcode 647

#palindromic #substrings#python
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[jonaskhanwald]

My day is incomplete without listening this:
"Hey everyone, welcome back! and let's write some more neat code today".

[seungjunlee]

Currently completed around 40% of the BLIND list. Thanks neetcode for always very clear explaination!

[IslamWaleed-ggmc]

14:06
what i did with 108 lines of code in cpp, he did in 16 lines of code in python

[drstoneftw]

Shorter solution that I found

class Solution:
def countSubstrings(self, s: str) -> int:

res = 0

def pl(l, r) -> int:
if l < 0 or r > len(s) - 1:
return 0
if s[l] == s[r]:
return 1 + pl(l - 1, r + 1)
return 0

for i in range(len(s)):
res += pl(i, i) + pl(i, i+1)

return res

[srinadhp]

I owe you one for making this concept so simple and crystal!

[shoooozzzz]

Top tier resource as I study algos for upcoming Google interview <3

[richard]

Bro dont stop posting videos, I will try to donate weekly for coffee and share link to atleast one person to support ur videos.

[RaviPrakash-dzfm]

Took help to understand the longest palindromic substring, but was able to solve this by myself. All thanks to the great way of teaching! Hats off man! I am a data scientist, who hadn't touched DSA for so long. But your 150 series has helped me a lot. I have my Google interview on 31st Jan. I don't know what will happen that day, but I'm pretty sure my DSA is way better than what it was a month ago.

[nehascorpion]

The best explanation on palindromic substrings so far! Thanks a ton!

[hwang]

After watching longest palindromic substring neetcode video came up with this:

class Solution:
def countSubstrings(self, s: str) -> int:
res = 0

def check(l, r):
nonlocal res

while l>= 0 and r < len(s) and s[l] == s[r]:
res += 1
l -= 1
r += 1



for i in range(len(s)):
check(i, i)
check(i, i+1)

return res

[BigFishMachine]

loving blind 75 series, learning a lot

[dnm]

Keep making videos bro, you’re really good! thank you so much!

[kirillzlobin]

The clearest explanation all over the Internet

[americandream]

What a smart solution! I see this question is categorized as a DP problem on LC and was struggling of thinking to solve in a DP way. Really like the way you explain a question and find a much simpler way to solve it!

[enkr]

You can also use Manacher's algorithm for O(n) and O(n) time space complexity!

[zaki_]

I was able to solve this today by myself because i'd seen you do it a couple of months back. Thanks for everything man!

[mostinho]

Great explanation but not sure why this is categorized as dp on your website

Same solution as longest palindrome problem (for each index expand outwards to find palindromes)

[johnnychang]

Beautiful and clean solution. Thank you. And I love your clean coding style!

[anusha]

thank you so much neetcode. It is such a relief that when i am stuck i know i can rely on you to help me out and understand something

[MP-nyep]

Terrific explanation. So well explained.