1, 'pid' = > 0, 'name' = > 'a'],    ['id' = > 2, 'pid' = > 0, 'name' = > 'b'],    ['id' = > 3, 'pid' = > 1, 'name' = > 'c'],    ['id' = > 4, 'pid' = > 2, 'name' = > 'd'],    ['id' = > 5, 'pid' = > 6, 'name' = > 'e'],    ['id' = > 6, 'pid' = > 4, 'name' = > 'f'],    ['id' = > 7, 'pid' = > 6, 'name' = > 'g'],    ['id' = > 8, 'pid' = > 6, 'name' = > 'h'],    ['id' = > 9, 'pid' = > 10, 'name' = > 'i'],    ['id' = > 10, 'pid' = > 8, 'name' = > 'j']]; function tree($list, $id = 'id', $pid = 'pid', $name = 'name') {    $data = [];    foreach($list as $row) {        $data[$row[$id]][$name] = $row[$name];        $data[$row[$pid]]['children'][$row[$id]] = & $data[$row[$id]];    }    return isset($data[0]['children']) ? $data[0]['children'] : [];}print_r(tree($nodes));$etime = microtime(true);echo '运行后内存：'.round(memory_get_usage() / 1024 / 1024, 2).'MB \r\n';$total = $etime - $stime; //计算差值echo "[页面执行时间：{
   $total} ]秒"; ?>