# LeetCode

# 5. Longest Palindromic Substring

# https://leetcode.com/problems/longest-palindromic-substring/description/

def mySolution(s) -> str:

array = []

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

for j in range(len(s)-i+1):

now = s[j:j+i]

if now == now[::-1]:

array.append(now)

# 좀 더 객관적인 for문 방식...

for start in range(len(s)):

for end in range(start + 1, len(s) + 1):

now = s[start:end]

if now == now[::-1]:

array.append(now)

return max(array, key=len)

def otherSolution(s) -> str:

# 팰린드롬은 홀수일 경우와 짝수일 경우를 고려해 주어야 함.

if len(s) < 2 or s == s[::-1]:

return s

def expand(left: int, right: int) -> str:

while left >= 0 and right < len(s) and s[left] == s[right]:

left -= 1

right += 1

return s[left+1:right]

result = ''

for i in range(len(s)):

result = max(result, expand(i, i+1), expand(i, i+2), key=len)

return result

mySolution("babad")