An explanation of the implementation process of PHP simple permutation and combination algorithm

This article mainly introduces the simple permutation and combination algorithm of PHP implementation, combined with specific application examples to analyze the implementation of the permutation algorithm and the use of skills, the need for friends can refer to the next

This paper introduces the application of simple permutation and combination algorithm of PHP implementation. Share to everyone for your reference, as follows:

First, the question:

Give you a 40 catty of watermelon, to 3 people, how many kinds of sub-method?

Second, PHP implementation code:

<?PHP$AA = Range (1,40), $BB = Array (), foreach ($aa as $k = = $val) {foreach ($aa as $v  ) {foreach ($aa as $vl    ) {
   $sum = $val + $v + $vl;      if ($sum = =) {        $bb [$k][0] = $val;        $BB [$k][1] = $v;        $BB [$k][2] = $VL;      }}}  Echo ' <pre> ';p rint_r ($BB); exit; >

The results of the operation are as follows:

Array ([0] = = Array ([0] = 1 [1] = [2] = 1) [1] = = Array ([0] = =  2 [1] = [2] = 1) [2] = = Array ([0] = 3 [1] = [2] = 1)      [3] = = Array ([0] = 4 [1] = + [2] = 1) [4] = = Array ([0] = 5 [1] [2] = 1) [5] = = Array ([0] = 6 [1] = [2] = 1) [6] =& Gt Array ([0] = 7 [1] = [2] = 1) [7] = = Array ([0] = 8 [1] = =    [2] = 1) [8] = = Array ([0] = 9 [1] = + [2] = 1) [9] = = Array      ([0] = [1] = [2] = 1) [Ten] = = Array ([0] = [1] = 28    [2] = 1) [One] = Array ([0] = [1] = [2] = 1) [] = = Array ([0] = 13      [1] [+] = [2] = 1) [+] = Array ([0] = [1] = [2] = 1)      [+] = Array ([0] = [1] = [2] = 1) [+] = Array ([0] = 16  [1] [+] [2] = 1) [+] = Array ([0] = [1] = [2] = 1)      [+] = Array ([0] = [1] = [2] = 1) [+] = Array ([0] = 19 [1] [2] = 1) [+]/= Array ([0] = [1] = [2] = 1) [      [0] = [1] = [2] = 1) [+] = Array ([0] = 22 [1] [+] = [2] = 1) [+]/= Array ([0] = [1] = [2] = 1) [2      3] = = Array ([0] = [1] = + [2] = 1) [[0] = = Array ([+] = 25 [1] = 14 [2]+ 1) [+] = Array ([0] = [1] = [2] = 1) [+] = = Array ( [0] = [1] = [2] = 1) [+] = Array ([0] = [1] = 11 [2] = > 1) [+] = Array ([0] = [1] = [2] = 1) [+] = + Array ([ 0] = [1] = 9 [2] = 1) [+] = = Array ([0] = [1] = 8 [2] =&gt ; 1) [+] = = Array ([0] = + [1] = 7 [2] = 1) [+] = = Array ([0] =&G T  [1] = 6 [2] = 1) [[[0] = [1] = +/-5 [2] = 1)      [+] = Array ([0] = [1] = 4 [2] = 1) [+] = Array ([0] = 36 [1] = 3 [2] = 1) [+] = = Array ([0] = Notoginseng [1] = 2 [2] = 1) [37 ] = = Array (     [0] = [1] = 1 [2] = 1))