Php implementation code of the Look And Say Sequence

For example:
The first number is: 1.
When you look at the first number, you can say 1, then the second number is: 11.
Looking at the second number, you can say 2 1, that is, the third number is 21.
Looking at the third number, you can say 1, 2, 1, and 1, that is, the fourth number is 1211.
Looking at the fourth number, you can say 1, 1, 1, 2, 2, 1, that is, the fifth number is 111221.
............
For detailed instructions, see: http://en.wikipedia.org/wiki/Look-and-say_sequence
The following code uses PHP to implement this sequence:
Copy codeThe Code is as follows:
Function look ($ str)
{
$ Len = strlen ($ str );
$ Count = 0;
$ Result = '';
$ Temp = $ str [0];
For ($ I = 0; $ I <$ len; $ I ++)
{
If ($ temp! = $ Str [$ I])
{
$ Result. = $ count. $ temp;

$ Temp = $ str [$ I];
$ Count = 1;
}
Else
{
$ Count ++;
}
}
$ Result. = $ count. $ temp;
Return $ result;
}

$ Test_str = "1 ";
Echo $ test_str. '</br> ';
For ($ I = 0; $ I <10; $ I ++)
{
$ Test_str = look ($ test_str );
Print $ test_str. "</br> ";
}

Note the for loop in the look function, when $ len-1, $ result does not accumulate the statistical results of the last digit, so accumulate again after the loop is complete.

Final output result:

1
11
21
1211
111221
312211
13112221
1113213211
31131211131221
13211311123113112211
11131221133112132113212221

Author: ywxgod