PHP使用数组查找范围和缺少的数字

Question

I have an array that looks like this:

    [0] => Array
    (
        [1] => 5
        [2] => 4
        [3] => 3
        [5] => 1
        [7] => 1
        [8] => 2
        [9] => 3
        [10] => 4
        [11] => 5
    )

[1] => Array
    (
        [1] => 6
        [2] => 5
        [4] => 3
        [5] => 2
        [6] => 1
        [8] => 3
        [9] => 4
        [10] => 5
        [11] => 6
    )

[2] => Array
    (
        [1] => 7
        [2] => 6
        [3] => 5
        [4] => 4
        [5] => 3
        [6] => 2
        [7] => 3
        [8] => 4
        [11] => 7
    )

I have an order of operations I'm trying to go through and I really don't know where to go from here. Any suggestions would be of great help.

1. First I give my class the number of items I want to return. For example here we'll use 4.

2. I want to loop through and find the item in the array that has the lowest value.

3. I want to look at the keys to the items around (it included) and be sure they're not missing a number if they are..reject it..

In this example the first one you would come to would be:

    [5] => 1

Now looking around it you see that the keys are missing some numbers. So no combination of 4 will get that to match any 4 in the proper order.

    [1] => 5
    [2] => 4
    [3] => 3
    [5] => 1  //this one
    [7] => 1
    [8] => 2
    [9] => 3

In this situation I want it to move onto the next case.

    [7] => 1

Notice this one will work due to the keys being 7,8,9,10.

    [7] => 1
    [8] => 2
    [9] => 3
    [10] => 4

This is what I would like returned first..but I don't even know how to begin to get there.

Further more there are situations like this..Say for example there are no 1's at all in the dataset..and only this lone 2 in the last one.

    [0] => Array
    (
        [1] => 5
        [2] => 4
        [3] => 3
        [5] => 3
        [7] => 3
        [8] => 3
        [9] => 3
        [10] => 4
        [11] => 5
    )

[1] => Array
    (
        [1] => 6
        [2] => 5
        [4] => 3
        [5] => 3
        [6] => 3
        [8] => 3
        [9] => 4
        [10] => 5
        [11] => 6
    )

[2] => Array
    (
        [1] => 7
        [2] => 6
        [5] => 3
        [6] => 2 // this one
        [7] => 3
        [8] => 4
        [11] => 7
    )

The following wont work:

    [6] => 2 // this one
    [7] => 3
    [8] => 4
    [11] => 7

but this one will:

        [5] => 3
        [6] => 2 // this one
        [7] => 3
        [8] => 4

I have no idea on how to approach this.. If someone could offer some advice it would be GREATLY appreciated. Thanks so much in advance.

Answer 1

The following assumes your data is in an array called $data. I'll describe it in steps, then pull it all together as a function.

Step 1 find the min value:

$minValue=min($data);

Step 2 loop through the array looking for all values that are that value:

foreach($data as $index => $value){

    if($value == $minValue){
         // $index is a candidate!
    }
}

Step 3 Check if $valuesToReturn entries exist after index:

    $success=true;

    for($i=1;$i<=$valuesToReturn;$i++){

        if(!array_key_exists($index + $i,$data)){

            // Candidate failed.
            $success=false;
            break;

        }

    }

Step 4 If the candidate was successful, return it.

    if($success){
        return $index;
    }

Putting that all together, we get this:

function findSuitableIndex($data,$valuesToReturn){

    // Min:
    $minValue=min($data);

    foreach($data as $index => $value){

        if($value == $minValue){
            // $index is a candidate!

            // test if index is actually suitable:
            $success=true;

            for($i=1;$i<=$valuesToReturn;$i++){

               if(!array_key_exists($index + $i,$data)){

                    // Candidate failed.
                    $success=false;
                    break;

                }

            }

            if($success){
                return $index;
            }

        }

    }

    // If we fell down here, we failed to find any successful results.
    return -1;
}

Working sample:

Code on eval.in