[ Javascript ] - 20140730-题目1

[ Javascript ] - 20140730-题目1

// 感谢[广州—坚壳]贡献
编码字符串，要求能解码，且只能编码为字母和数字，
要求得到最短的编码长度。
如：
setcode('你好a')  -> ‘232abc';
getcode('232abc')  -> '你好a'

PS:
1. 回复时注意加上下面这句话，才会有语法高亮或格式缩进。
```javascript
// you code
```
2. 粘贴代码时请使用shift+tab，缩进前面的空白。  

function isString(variable) {
    return Object.prototype.toString.call(variable).indexOf('String') != -1;
}

function isNumeric(variable) {
    return !isNaN(parseFloat(variable)) && isFinite(variable);
}

function stringEncode(string) {
    string = isString(string) || isNumeric(string) ? String(string) : '';

    var code,
        i = 0,
        code_string = '',
        len = string.length;

    while(i < string.length) {
        code = string.charCodeAt(i);
        code_string += '' + String(code).length + code;
        i++;
    }

    return string10to62(code_string);
}

function stringDecode(code) {
    var i = 0,
        code_len,
        decode_string = '';
    code = String(string62to10(code));
    while(i < code.length) {
        code_len = +code.charAt(i);
        i++;
        decode_string += String.fromCharCode(+code.substr(i, code_len));
        i += code_len;
    }
    return decode_string;
}
function string10to62(number) {
    var chars = '0123456789abcdefghigklmnopqrstuvwxyzABCDEFGHIGKLMNOPQRSTUVWXYZ'.split(''),
        radix = chars.length,
        qutient = +number,
        arr = [];
    do {
        mod = qutient % radix;
        qutient = (qutient - mod) / radix;
        arr.unshift(chars[mod]);
    } while (qutient);
    return arr.join('');
}

function string62to10(number_code) {
    var chars = '0123456789abcdefghigklmnopqrstuvwxyzABCDEFGHIGKLMNOPQRSTUVWXYZ',
        radix = chars.length,
        number_code = String(number_code),
        len = number_code.length,
        i = 0,
        origin_number = 0;
    while (i < len) {
        origin_number += Math.pow(radix, i++) * chars.indexOf(number_code.charAt(len - i) || 0);
    }
    return origin_number;
}

来发没压缩字符串的

楼上的这个stringEncode传的字符串越多。执行函数出来的return 的字符串也越多，这样是不是失去意义了！！，如果这样的话 随便都可以弄一个了

stringEncode('dgd')
"310031033100"
stringEncode('dgddsfsf')
"31003103310031003115310231153102"
stringEncode('dgddsfsfdgdgdg')
"31003103310031003115310231153102310031033100310331003103"
stringEncode('dgddsfsfdgdgdg453t3tg')
"31003103310031003115310231153102310031033100310331003103252253251311625131163103"