Q:
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
0
s. 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"
A:
就是递归右移 >>>
public class Solution {
public String toHex(int num) {
int cur = num & 15;
num = num>>>4;
return ( (num==0)?"":toHex(num) ) + ( (cur<=9)?(char)(cur+'0'):(char)(cur-10 + 'a') );
}
}
Errors:
由于3目运算符的优先级比较低,因此要尽量把它们括号起来用。
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
0
s. 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"
public class Solution { public String toHex(int num) { int cur = num & 15; num = num>>>4; return ( (num==0)?"":toHex(num) ) + ( (cur<=9)?(char)(cur+'0'):(char)(cur-10 + 'a') ); } }
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