Array comparison and corresponding relationship are obtained. how can this problem be solved?

Array comparison and obtain the known correspondence array a: $ a & nbsp; array & nbsp; (& nbsp; 0 & nbsp; & gt; & nbsp; & nbsp; array & nbsp; (& nbsp; packageno & nbsp; & gt; & nbsp; S2Y140805025, & nbsp; & nbsp; & array comparison and correspondence
Known array:

$a = array (
  0 => 
  array (
    'packageno' => 'S2Y140805025',
    'type' => 'ECS0-235',
    'cust_no' => '12654172',
    'lotno' => '4212',
  ),
  1 => 
  array (
    'packageno' => 'S2Y140805025',
    'type' => 'ECS0-235',
    'cust_no' => '12654172',
    'lotno' => '4214',
  ),
  2 => 
  array (
    'packageno' => 'SYS140804073',
    'type' => 'ECS0-235',
    'cust_no' => '12654172',
    'lotno' => '4212',
  ),
  3 => 
  array (
    'packageno' => 'SYS140804073',
    'type' => 'ECS0-235',
    'cust_no' => '12654172',
    'lotno' => '4213',
  ),
  4 => 
  array (
    'packageno' => 'SYS140731064',
    'type' => 'ECS1-713',
    'cust_no' => '12657727',
    'lotno' => '4154',
  ),
  5 => 
  array (
    'packageno' => 'SYS140731064',
    'type' => 'ECS1-713',
    'cust_no' => '12657727',
    'lotno' => '4210',
  ),
  6 => 
  array (
    'packageno' => 'SYS140801090',
    'type' => 'ECS1-713',
    'cust_no' => '12657727',
    'lotno' => '4200',
  ),
  7 => 
  array (
    'packageno' => 'SYS140801090',
    'type' => 'ECS1-713',
    'cust_no' => '12657727',
    'lotno' => '4210',
  ),
);

There is a correspondence relationship, such as packageno S2Y140805025 corresponding to lotno 4212,4214 (type is ECS0-235, cust_no is 12654172)

Also known array B:

$b = array (
  0 => 
  array (
    'type' => 'ECS0-235',
    'cust_no' => '12654172',
    'lotno' => '4211',
  ),
  1 => 
  array (
    'type' => 'ECS0-235',
    'cust_no' => '12654172',
    'lotno' => '4212',
  ),
  2 => 
  array (
    'type' => 'ECS0-235',
    'cust_no' => '12654172',
    'lotno' => '4213',
  ),
  3 => 
  array (
    'type' => 'ECS0-235',
    'cust_no' => '12654172',
    'lotno' => '4214',
  ),
  4 => 
  array (
    'type' => 'ECS0-235',
    'cust_no' => '12654172',
    'lotno' => '4216',
  ),
  5 => 
  array (
    'type' => 'ECS1-713',
    'cust_no' => '12657727',
    'lotno' => '4154',
  ),
  6 => 
  array (
    'type' => 'ECS1-713',
    'cust_no' => '12657727',
    'lotno' => '4200',
  ),
  7 => 
  array (
    'type' => 'ECS1-713',
    'cust_no' => '12657727',
    'lotno' => '4210',
  ),
);

Q: When the types of arrays a and B are the same as those of cust_no, whether the lotno corresponding to packageno in array a is continuous in array B. if not continuous, packageno is displayed.

What should I do?
------ Solution --------------------

Function foo ($ a, $ B ){
Foreach ($ a as $ v ){
$ C [] = array_search ($ v, $ B );
}
For ($ I = 1; $ I
 If (abs ($ c [$ I]-$ c [$ i-1])! = 1 ){
Return 'nonconsecutive ';
}
}
Return 'continous ';