405. Convert a Number to Hexadecimal#2

Solution#2

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.append(map[num & 15]);
            num = (num >>> 4);
        }
        return sb.reverse().toString();
    }
}

Solution#1



Problem#2

• 帶符號右移，無符號右移

Problem#1

• 試着用位操作去解決，而不是通過除法