编码/压缩重复整数序列 [英] Encode/compress sequence of repeating integers
问题描述
我有非常长的整数序列,看起来像这样(任意长度!):
0000000001110002220033333
现在我需要一些算法将这个字符串转换成压缩的像
a9b3a3c3a2d5
这意味着a 9次,然后b 3次,然后3次等等,其中a表示0,b表示1,c表示2,d表示3.
<你会怎么做的?
到目前为止没有什么合适的想法,我没有运气与谷歌,因为我真的不知道要搜索什么。这种编码/压缩叫什么?
PS:我将使用 PHP 执行编码,并在 JavaScript 中解码。
编辑:谢谢大家!
我最后使用此函数进行编码:
numStringToRle($ s){
$ rle ='';
$ count = 1;
$ len = strlen($ s);
for($ i = 0; $ i <$ len; $ i ++){
if($ i!= $ len&& isset($ s [$ i + 1])& ;& $ s [$ i] == $ s [$ i + 1]){
$ count ++;
} else {
$ rle。= chr($ s [$ i] + 97)($ count == 1?'':$ count);
$ count = 1;
}
}
return $ rle;
}
解码:
var decodeCoords = function(str){
str = str.replace(/(。)(\d +)/ g,function ,x,n){
return new Array(parseInt(n,10)+ 1).join(x);
});
return str。
replace(/ a / g,'0')。
replace(/ b / g,'1')。
replace(/ c / g,'2')。
replace(/ d / g,'3');
};
它被称为运行长度编码
PHP中的基本编码器:
function numStringToRle($ s){
$ rle =''
$ count = 1;
$ len = strlen($ s);
for($ i = 0; $ i <$ len; $ i ++){
if($ i!= $ len& $ s [$ i] == $ s [$ i + 1]){
$ count ++;
} else {
$ rle。= chr($ s [$ i] + 97)。
$ count = 1;
}
}
return $ rle;
}
警告它会对类似
123456789123456789
你将要处理一个可能有很多单个单个字符的字符串,最好添加一些复杂性,如果运行的长度为1,不写入运行的长度。
// change
$ rle。= chr($ s [$ i] + 97)。
//到
$ rle。= chr($ s [$ i] + 97)($ count == 1?'':$ count);
//或
$ rle。= chr($ s [$ i] + 97)
if($ count!= 1){
$ rle。 = $ count;
}
I have very long integer sequences that look like this (arbitrary length!):
0000000001110002220033333
Now I need some algorithm to convert this string into something compressed like
a9b3a3c3a2d5
Which means "a 9 times, then b 3 times, then a 3 times" and so on, where "a" stands for 0, "b" for 1, "c" for 2 and "d" for 3.
How would you do that? So far nothing suitable came to my mind, and I had no luck with google because I didn't really know what to search for. What is this kind of encoding / compression called?
PS: I am going to do the encoding with PHP, and the decoding in JavaScript.
Edit: Thank you all!
I ended up with this function for encoding:
protected function numStringToRle($s){
$rle = '';
$count = 1;
$len = strlen($s);
for($i = 0; $i < $len; $i++){
if($i != $len && isset($s[$i+1]) && $s[$i] == $s[$i+1]){
$count++;
} else {
$rle .= chr($s[$i] + 97).( $count == 1 ? '' : $count);
$count = 1;
}
}
return $rle;
}
And that for decoding:
var decodeCoords = function(str) {
str = str.replace(/(.)(\d+)/g, function(_, x, n) {
return new Array(parseInt(n, 10) + 1).join(x);
});
return str.
replace(/a/g, '0').
replace(/b/g, '1').
replace(/c/g, '2').
replace(/d/g, '3');
};
It is called Run Length Encoding
Basic encoder in PHP:
function numStringToRle($s){
$rle = '';
$count = 1;
$len = strlen($s);
for ( $i = 0; $i < $len; $i++ ){
if ( $i != $len && $s[$i] == $s[$i+1] ){
$count++;
}else{
$rle .= chr($s[$i] + 97).$count;
$count = 1;
}
}
return $rle;
}
Be warned it will preform badly issues with a string like
123456789123456789
If you were going to be handling a string that may have a lot of individual single characters you would be better to add some complexity and not write the length of the run if the length of the run is 1.
//change
$rle .= chr($s[$i] + 97).$count;
//to
$rle .= chr($s[$i] + 97).( $count == 1 ? '' : $count );
//or
$rle .= chr($s[$i] + 97)
if ( $count != 1 ){
$rle .= $count;
}
这篇关于编码/压缩重复整数序列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!