101 - 数字转换为16进制数

题目

给定一个整数，编写一个算法将这个数转换为十六进制数。对于负整数，我们通常使用 补码运算 方法。

注意:

1. 十六进制中所有字母(a-f)都必须是小写。

2. 十六进制字符串中不能包含多余的前导零。如果要转化的数为0，那么以单个字符'0'来表示；对于其他情况，十六进制字符串中的第一个字符将不会是0字符。

3. 给定的数确保在32位有符号整数范围内。

4. 不能使用任何由库提供的将数字直接转换或格式化为十六进制的方法。

示例 1：

输入: 26

输出: "1a"

示例 2：

输入: -1

输出: "ffffffff"

解答

&

https://leetcode.com/problems/convert-a-number-to-hexadecimal/discuss/89261/easy-10-line-python-solution-with-inline-explanation

class Solution:
    def toHex(self, num: int) -> str:
        if num == 0:
            return "0"
        data = "0123456789abcdef"
        result = ""
        for i in range(8):
            result = data[num & 15] + result
            num >>= 4
            if num == 0:
                break
        return result

Runtime: 36 ms, faster than 70.37% of Python3 online submissions for Convert a Number to Hexadecimal.

Memory Usage: 13.8 MB, less than 50.00% of Python3 online submissions for Convert a Number to Hexadecimal.

var toHex = function (num) {
  if (num == 0) {
    return "0"
  }
  const data = "0123456789abcdef"
  result = ""
  for (let i = 0; i < 8; i++) {
    result = data[num & 15] + result
    num >>= 4
    if (num === 0) {
      break
    }
  }
  return result
};

Runtime: 44 ms, faster than 98.65% of JavaScript online submissions for Convert a Number to Hexadecimal.

Memory Usage: 33.8 MB, less than 100.00% of JavaScript online submissions for Convert a Number to Hexadecimal.

func toHex(num int) string {
    if num == 0 {
        return "0"
    }
    data := "0123456789abcdef"
    var result string
    for i := 0; i < 8; i++ {
        result = string(data[num&15])+result
        num >>=4
        if num ==0 {
            break
        }
    }
    return result
}

Runtime: 0 ms, faster than 100.00% of Go online submissions for Convert a Number to Hexadecimal.

Memory Usage: 1.9 MB, less than 100.00% of Go online submissions for Convert a Number to Hexadecimal.

%

作者：trklnejQEZ 链接：https://leetcode-cn.com/problems/convert-a-number-to-hexadecimal/solution/python-chao-jian-dan-shi-xian-bao-ni-ke-yi-kan-don/

class Solution:
    def toHex(self, num: int) -> str:
        if num == 0:
            return "0"
        if num < 0:
            max_int = 0xffffffff + 0x00000001
            num += max_int
        data = "0123456789abcdef"
        result = ""
        while num != 0:
            result = data[num % 16] + result
            num //= 16
        return result

Runtime: 32 ms, faster than 90.74% of Python3 online submissions for Convert a Number to Hexadecimal.

Memory Usage: 13.8 MB, less than 50.00% of Python3 online submissions for Convert a Number to Hexadecimal.

func toHex(num int) string {
    if num == 0 {
        return "0"
    }
    if num < 0 {
        num += 0xffffffff + 0x00000001
    }
    data := "0123456789abcdef"
    var result string
    for num != 0 {
        result = string(data[num%16]) + result
        num /= 16
    }
    return result
}

Runtime: 0 ms, faster than 100.00% of Go online submissions for Convert a Number to Hexadecimal.

Memory Usage: 2 MB, less than 100.00% of Go online submissions for Convert a Number to Hexadecimal.

var toHex = function (num) {
  if (num == 0) {
    return "0"
  }
  if (num < 0) {
    num += 0xffffffff + 0x00000001
  }
  const data = "0123456789abcdef"
  result = ""
  while (num != 0) {
    result = data[num % 16] + result
    num = Math.floor(num / 16)
  }
  return result
};

Runtime: 44 ms, faster than 98.65% of JavaScript online submissions for Convert a Number to Hexadecimal.

Memory Usage: 33.9 MB, less than 100.00% of JavaScript online submissions for Convert a Number to Hexadecimal.