Given an integer, write an algorithm to convert it to hexadecimal. For negative integer, two’s complement method is used.
Note:
- All letters in hexadecimal (a-f) must be in lowercase.
- The hexadecimal string must not contain extra leading 0s. If the number is zero, it is represented by a single zero character '0'; otherwise, the first character in the hexadecimal string will not be the zero character.
- The given number is guaranteed to fit within the range of a 32-bit signed integer.
- You must not use any method provided by the library which converts/formats the number to hex directly.
Example 1:
Input:
26
Output:
"1a"
Example 2:
Input:
-1
Output:
"ffffffff"
class Solution:
def toHex(self, num):
"""
:type num: int
:rtype: str
"""
def positive(num):
res = []
while True:
res.append(num%16)
num = num//16
if num==0:
break
for i in range(len(res)):
if res[i]<10:
res[i] = str(res[i])
else:
res[i] = chr(87+res[i])
return ''.join(res)[::-1]
def negative(num):
return positive(4294967296+num)
if num>=0:
return positive(num)
else:
return negative(num)