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:

PHP Code Editor:
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Previous: Write a PHP program to compute the amount of the debt in n months.
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 )
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