# Time: O(1)

# Space: O(1)

# Given an integer, return its base 7 string representation.

#

# Example 1:

# Input: 100

# Output: "202"

# Example 2:

# Input: -7

# Output: "-10"

# Note: The input will be in range of [-1e7, 1e7].

class Solution(object):

def convertToBase7(self, num):

if num < 0:

return '-' + self.convertToBase7(-num)

result = ''

while num:

result = str(num % 7) + result

num //= 7

return result if result else '0'

class Solution2(object):

def convertToBase7(self, num):

"""

:type num: int

:rtype: str

"""

if num < 0:

return '-' + self.convertToBase7(-num)

if num < 7:

return str(num)

return self.convertToBase7(num // 7) + str(num % 7)