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PHP Exercises: Reads an integer n and find the number of combinations

PHP: Exercise-51 with Solution

Write a PHP program which reads an integer n and find the number of combinations of a,b,c and d (0 ≤ a,b,c,d ≤ 9) where (a + b + c + d) will be equal to n.

Input:
n (1 ≤ n ≤ 50) .

Sample Solution: -

PHP Code:

<?php
 while (($input = trim(fgets(STDIN))) !== '') {
    $input = intval($input);
    $count = 0;
    for ($i=0; $i < 10; $i++) { 
        for ($j=0; $j < 10; $j++) { 
            for ($k=0; $k < 10; $k++) { 
                for ($l=0; $l < 10; $l++) { 
                    if ($i + $j + $k +$l === $input) {
                        $count++;
                    }
                }
            }
        }
    }
    echo "\nNumber of combinations of a,b,c and d: ";
    echo $count."\n";
}
?>

Sample Output: 

Number of combinations of a,b,c and d: 56

Flowchart:

Flowchart: Reads an integer n and find the number of combinations

PHP Code Editor:

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Next: Write a PHP program to print the number of prime numbers which are less than or equal to a given integer.

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PHP: Tips of the Day

Returns all elements in an array except for the first one

Example:

<?php
function tips_tail($items)
{
  return count($items) > 1 ? array_slice($items, 1) : $items;
}

print_r(tips_tail([1, 5, 7]));
?>

Output:

Array
(
    [0] => 5
    [1] => 7
)