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Playing Hacks and Stuffs!

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Reverse Only Letters

Given a string s, reverse the string according to the following rules:

• All the characters that are not English letters remain in the same position.
• All the English letters (lowercase or uppercase) should be reversed.

Return s after reversing it.

My approach is this:

• Initialize two pointers left and right which would hold the 0th and last index len(s)-1 value
• In a while loop I’ll check:
  • To check for if the value of s[left] of the string is not alpha() I’ll make a while loop that checks for that and I’ll increment the left pointer by 1
  • To check for if the value of s[right] of the string is not alpha() I’ll make a while loop that checks for that and I’ll decrement the right pointer by 1
  • The point at which they exist two values where s[left] and s[right] is alpha() I’ll then swap them i.e I’ll set s[left], s[right] = s[right], s[left]
• Then I’ll increment the left pointer by 1 and decrement the right pointer by 1 to keep the process going till I reach the condition where left > right then the loop finishes and I get a reversed string that meets the condition

Solve Script: link

Leetcode Submission Script

class Solution:
    def reverseOnlyLetters(self, s: str) -> str:
        s = list(s)

        left, right = 0, len(s)-1

        while left < right:

            while left < right and s[left].isalpha() == False:
                left += 1

            while left < right and s[right].isalpha() == False:
                right -= 1
            
            if s[left].isalpha() and s[right].isalpha():
                s[left], s[right] = s[right], s[left]

            
            left += 1
            right -= 1
        
        r = "".join(s)

        return r