class Solution(object):
def toHex(self, num):
"""
:type num: int
:rtype: str
"""
if num == 0:
return '0'
# letter map
mp = '0123456789abcdef'
ans = ''
for _ in range(8):
# get last 4 digits
# num & 1111b
n = num & 15
# hex letter for current 1111
c = mp[n]
ans = c + ans
# num = num / 16
num = num >> 4
#strip leading zeroes
return ans.lstrip('0')
# def toHex(self, num):
# def tohex(val, nbits):
# return hex((val + (1 << nbits)) % (1 << nbits))
# return tohex(num, 32)[2:]
# def toHex(self, num, h=''):
# return (not num or h[7:]) and h or self.toHex(num / 16, '0123456789abcdef'[num % 16] + h)
