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"
Solution in python:
class Solution:
def toHex(self, num: int) -> str:
clist = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', ]
result = ""
mask = 0xf
n = 32
while n > 0:
temp = num & mask
result = clist[temp] + result
num >>= 4
n -= 4
for i in range(len(result)):
if result[i] != '0':
return result[i:]
return "0"
留言