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"
该题目难度不大，只要依次把末4位转成16进制，去除0后，反过来输出即可，>>>的使用可以省去很多麻烦。
public class Solution { public String toHex(int num) { if(num==0) return "0"; char[] hex=new char[8]; int i=0; while(num!=0) { hex[i]=(char)(num&15); if(hex[i]<10) hex[i]+='0'; else hex[i]+='a'-10; num=num>>>4; i++; } StringBuffer strb=new StringBuffer(); while(i>0) { strb.append(String.valueOf(hex[i-1])); i--; } return strb.toString(); } }