PHP不使用递归的无限级分类简单实例

<?php
$list = array(
  array('id'=>1, 'pid'=>0, 'deep'=>0, 'name'=>'test1'),
  array('id'=>2, 'pid'=>1, 'deep'=>1, 'name'=>'test2'),
  array('id'=>3, 'pid'=>0, 'deep'=>0, 'name'=>'test3'),
  array('id'=>4, 'pid'=>2, 'deep'=>2, 'name'=>'test4'),
  array('id'=>5, 'pid'=>2, 'deep'=>2, 'name'=>'test5'),
  array('id'=>6, 'pid'=>0, 'deep'=>0, 'name'=>'test6'),
  array('id'=>7, 'pid'=>2, 'deep'=>2, 'name'=>'test7'),
  array('id'=>8, 'pid'=>5, 'deep'=>3, 'name'=>'test8'),
  array('id'=>9, 'pid'=>3, 'deep'=>2, 'name'=>'test9'),
);
function resolve($list) {
  $newlist = $manages = $deeps = $indeeps = array();
  foreach ($list as $row) {
    $newlist[$row['id']] = $row;
  }
  $list = null;
  foreach ($newlist as $row) {
    if (! isset($manages[$row['pid']]) || ! isset($manages[$row['pid']]['children'][$row['id']])) {
      if ($row['pid'] > 0 && ! isset($manages[$row['pid']]['children'])) $manages[$row['pid']] = $newlist[$row['pid']];
      $manages[$row['pid']]['children'][$row['id']] = $row;
    }
    if (! isset($indeeps[$row['deep']]) || ! in_array($row['id'], $indeeps[$row['deep']])) {
      $indeeps[$row['deep']][] = array($row['pid'], $row['id']);
    }
  }
  krsort($indeeps);
  array_shift($indeeps);
  foreach ($indeeps as $deep => $ids) {
    foreach ($ids as $m) {
      // 存在子栏目的进行转移
      if (isset($manages[$m[1]])) {
        $manages[$m[0]]['children'][$m[1]] = $manages[$m[1]];
        $manages[$m[1]] = null;
        unset($manages[$m[1]]);
      }
    }
  }
  return $manages[0]['children'];
}

function resolve2(& $list, $pid = 0) {
  $manages = array();
  foreach ($list as $row) {
    if ($row['pid'] == $pid) {
      $manages[$row['id']] = $row;
      $children = resolve2($list, $row['id']);
      $children && $manages[$row['id']]['children'] = $children;
    }
  }
  return $manages;
}