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I am a newbie in PHP. I have been given the following as homework: Write a php function called findMissing that receives 3 parameters. The function must determine and return a missing number in an array of numbers – note: only one number will be missing from the series of numbers, the number you must find. All the numbers will be integers. ◦ $start : This will be an integer indicating the minimum number the array can contain. ◦ $end : This will be an integer indicating the maximum number the array can contain. ◦ $numbers : An array with numbers between $start and $end. This array might not be sorted. There is no guarantee that the first or last number in the array will correspond to $start and $end respectively. $start and $end are inclusive in the range of numbers As an example: findMissing(1, 5, array(2,5,1,3)); must return 4 as the missing number. The array $numbers will always contain $end - $start number of elements.

So far I have the following code:

 function findMissing($start,$end,$numbers)
        {
            if ($start >0 && $end >0){

                for ($x=0; $x<=end; $x++) {
                  $numbers=array($x);         
             } 
               }    
            foreach ($numbers as $value){

                echo $value;
            }
        }

Please help because I am stuck

Shankar Narayana Damodaran
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user3572396
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3 Answers3

0

When you are faced with a problem, and this is not just for programming, first thing first is you have to picture the solution in your head and see it working.

Given this task a few ideas come to mind:

You can sort the array and loop through it, as soon as a number that's not equal to the previous number + 1 occurs, you can safely say that previous number + 1 is your missing number.

Another way you can solve this is by looping in the range of $start to $end and check if each value is in the given array with in_array(). As soon as you encounter a value that's not, needless to say, this is your number.

If your goal isn't to learn, but to just get rid of that homework, drop a comment I'll scribble the function for you.

php_nub_qq
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0

dude!! here is a simple solution for that add all numbers between $start and $end as $sumAll and also add all the elements of that array as $sum now $missingNumber = $sumAll-$sum !! Do it it would be fun :)

Sahil Sarpal
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You may try this

<?php

$start      = 1;
$end        = 5;
$numbers    = array(2,5,1,3);

findMissing($start,$end,$numbers);

function findMissing($start,$end,$numbers)
{
    $range[$start-1] = 0;   // here, it will be $range[0] = 0;
    for($i=$start; $i<=$end; $i++)
    {
        $range[$i] = $range[$i-1]+1;
        if(!in_array($range[$i], $numbers))
        {
            echo '<br> Missing no= '. $i;
            //return $i;
        }

    }
}
?>

Hope this will be helpful...

DB02
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