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:
public class Solution {
public String toHex(int num) {
if(num==0) return "0";
String[] map = new String[]{"0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"};
StringBuilder sb = new StringBuilder();
while(num!=0){
sb.insert(0,map[num&15]);
num = num>>>4;
}
return sb.toString();
}
}