将数字转换为尽可能短的字符串，同时保留唯一性 [英] Convert a number to the shortest possible character string while retaining uniqueness

问题描述

我有一个数字，比如123456，我需要将它映射到字符串，任何字符串。地图函数的唯一约束是：

I have a number, say "123456", and I need to map it to a string, any string. The only constraint on the map functions are:

• 每个数字必须映射到唯一的字符串（这意味着字符串可以任意长）


• 字符串只能包含0-9，az，AZ

什么地图功能会产生最短的字符串？

What map function would produce the shortest strings?

首选JavaScript解决方案。

Solutions in JavaScript are preferred.

注意：显然最简单的解决方案是使用原始号码，所以请确保您的解决方案比这更好。

Note: Clearly the simplest solution is to use the original number, so make sure you solution does better than that.

推荐答案

您可能需要使用 Base 36 或 Base 62 。

对于不区分大小写的字母数字字符，Base 36将是最紧凑的，但如果你想利用区分大小写，Base 62的紧凑性会大约增加20％。

Base 36 would be the most compact for case-insensitive alphanumerical characters, but if you want to exploit case-sensitivity, Base 62 would be approximately 20% more compact.

对于Base 36，您可以轻松使用JavaScript的 Number.toString（radix）方法，如下所示：

For Base 36, you can easily use JavaScript's Number.toString(radix) method, as follows:

var n = 123456;
n.toString(36); // returns: "2n9c"

对于Base 62，您可能需要检查此论坛帖子。基本上你应该能够做到以下几点：

For Base 62, you may want to check this forum post. Basically you should be able to do the following:

Number.prototype.toBase = function (base) {
    var symbols = 
    "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ".split("");
    var decimal = this;
    var conversion = "";

    if (base > symbols.length || base <= 1) {
        return false;
    }

    while (decimal >= 1) {
        conversion = symbols[(decimal - (base * Math.floor(decimal / base)))] + 
                     conversion;
        decimal = Math.floor(decimal / base);
    }

    return (base < 11) ? parseInt(conversion) : conversion;
}

var n = 123456;
n.toBase(62); // returns: "w7e"

这篇关于将数字转换为尽可能短的字符串，同时保留唯一性的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！