Zigzag - Gemini

class Solution(object):
    def convert(self, s, numRows):
        """
        :type s: str
        :type numRows: int
        :rtype: str
        """
        if numRows == 1:
         return s  # No need to convert if there's only one row

        rows = [''] * numRows  # Create empty rows to store the characters
        currentRow = 0
        goingDown = True

        for char in s:
            rows[currentRow] += char  # Add the character to the current row
            if goingDown:
                currentRow += 1  # Move down if going down
                if currentRow == numRows - 1:
                    goingDown = False  # Change direction at the bottom
            else:
                currentRow -= 1  # Move up if going up
                if currentRow == 0:
                    goingDown = True  # Change direction at the top

        return ''.join(rows)  # Concatenate the characters from all rows