Have just encountered a tricky algorithm problem, solving

Solving

Reply to discussion (solution)

$a = Array (1,2,2,3,1,2,3,1,1), $st = Array (1 = 0), $d = 1;foreach ($a as $v) {  @ $st [$v]++;  if ($v >= $d) {    $d = $v;  } else{    while ($v < $d) {      unset ($st [$d--]);    }  }  

Array
(
[0] = 1
[1] = 1.1
[2] = 1.2
[3] = 1.2.1
[4] = 2
[5] = 2.1
[6] = 2.1.1
[7] = 3
[8] = 4
)

Sorry, I didn't see what it meant. ......。。 ...。 ............。 ......。。 ...。 ......。。 ...。 ......。 ......。 .........

$a = Array (1,2,2,3,1,2,3,1,1), $st = Array (1 = 0), $d = 1;foreach ($a as $v) {  @ $st [$v]++;  if ($v >= $d) {    $d = $v;  } else{    while ($v < $d) {      unset ($st [$d--]);    }  }  

Array
(
[0] = 1
[1] = 1.1
[2] = 1.2
[3] = 1.2.1
[4] = 2
[5] = 2.1
[6] = 2.1.1
[7] = 3
[8] = 4
)

Moderator, thank you for your answer, if so, can you talk about your ideas ah, thank you very much

Sorry, I didn't see what it meant. ......。。 ...。 ............。 ......。。 ...。 ......。。 ...。 ......。 ......。 .........

The topic is actually a directory layout problem, you can see that the priority determines the size of the title of the display

$a = array (1,2,2,3,1,2,3,1,1); Represents the level at which the node is located
$st = Array (1 = 0); Stores the current ordinal number of each layer
$d represents the current level

Well, thanks to the moderator's explanation, I'll do a good research, first to distribute the

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