Longest Palindrome in a String || Program 20 || Competitive Coding || Learning Monkey ||

Longest Palindrome in a String
In this class, We discuss the Longest Palindrome in a String.
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Question:
Given a string S.
Find the longest palindromic substring in the string S.
If multiple substrings are of the same length, display the substring starting with the least index.
Time complexity: O(|S|^2)
Space complexity: O(1)
Example:
Input: aaaabbaa
Output: aabbaa
Example 2:
Input: abc
Output: a
If no palindrome exists in the string, display the first character.
Logic:
We explained the logic in the above video.
Code: less than and greater than symbols are changed to lt and gt
class Solution:
def longestPalin(self, S):
# code here
s = S
n = len(s)

def LP(l,r):
while rltn and lgt=0:
if s[l]!=s[r]:break
l-=1
r+=1
return l+1 , r

start, end =0,0

for i in range(n):
#odd case
l, r = LP(i,i)
if (r-l)gt(end-start):
end = r
start = l

#even case
l, r = LP(i,i+1)
if (r-l)gt(end-start):
end = r
start = l

return s[start:end]
s=input()
ob=Solution()
k=ob.longestPalin(s)
print(k)

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