php简单的两表合并成新表的实现过程

<?php
include_once "biao.php";  //引入类文件
  $phpig = new union();   //实例化类

  $lista = $phpig->lista = array(3, 5, 8, 11);
  $listb = $phpig->listb = array(2, 6, 8, 9, 11, 15);
  $listc = $phpig->listc;

  $lena = $phpig->getlenght($lista); //取得表大小
  $lenb = $phpig->getlenght($listb);
  $i = $j = 0;
  while($i < $lena && $j < $lenb) {
    $ea = $phpig->getelement($lista, $i);
    $eb = $phpig->getelement($listb, $j);
    if($ea <= $eb) {
      $listc = $phpig->listinsert($listc, $ea);
      ++$i;
    } else {
      $listc = $phpig->listinsert($listc, $eb);
      ++$j;
    }
  }
  while($i < $lena) {
    $ea = $phpig->getelement($lista, $i);
    $listc = $phpig->listinsert($listc, $ea);
    ++$i;
  }
  while($j < $lenb) {
    $eb = $phpig->getelement($listb, $j);
    $listc = $phpig->listinsert($listc, $eb);
    ++$j;
  }
  print_r($listc);
?>