- Convert a Number to Hexadecimal Easy
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Share 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"
思路：位运算,16进制，把num与0b1111与运算，获取字典表下标（‘0123456789abcdef’），组合
代码:python3
class Solution:
def toHex(self, num: int) -> str:
if num==0:return '0'
np='0123456789abcdef'
result=''
while num:
s=num&0xf
result = np[s]+result
num = num>>4 if num>0 else(num%0x100000000)>>4
return result
