<?php
$input = array("red", "green", "blue", "yellow");
array_splice($input, 2);
// $input is now array("red", "green")

$input = array("red", "green", "blue", "yellow");
array_splice($input, 1, -1);
// $input is now array("red", "yellow")

$input = array("red", "green", "blue", "yellow");
array_splice($input, 1, count($input), "orange");
// $input is now array("red", "orange")

$input = array("red", "green", "blue", "yellow");
array_splice($input, -1, 1, array("black", "maroon"));
// $input is now array("red", "green",
//          "blue", "black", "maroon")

$input = array("red", "green", "blue", "yellow");
array_splice($input, 3, 0, "purple");
// $input is now array("red", "green",
//          "blue", "purple", "yellow");
?>

------解决方案--------------------

PHP code

$data = array(
    array("Id" => "24", "FromMid" => "157", "ToMid" => "157"),
    array("Id" => "22", "FromMid" => "157", "ToMid" => "176"),
    array("Id" => "4", "FromMid" => "157", "ToMid" => "25"),
    array("Id" => "1", "FromMid" => "25", "ToMid" => "157")
);

$markList = array();
foreach ($data as $key => $val) {
    $posi = md5($val['FromMid'] . $val['ToMid']);
    $anti = md5($val['ToMid'] . $val['FromMid']);
    if (isset($markList[$posi])