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PHP Exercises: Create maximum number of regions obtained by drawing n given straight lines

PHP: Exercise-67 with Solution

If you draw a straight line on a plane, the plane is divided into two regions. For example, if you pull two straight lines in parallel, you get three areas, and if you draw vertically one to the other you get 4 areas.
Write a PHP program to create maximum number of regions obtained by drawing n given straight lines.

Input: (1 ≤ n ≤ 10,000)

Sample Solution: -

PHP Code:

<?php
while (($line = trim(fgets(STDIN))) !== '') {
    $n = (int)$line;
    $result = 2;
    for ($i = 2; $i <= $n; $i++) {
        $result += $i;
    } 
    echo 'Maximum number of regions: ';
    echo $result, PHP_EOL;
}
?>

Sample Input:
5

Sample Output: 

Maximum number of regions: 16

Flowchart:

Flowchart: Create maximum number of regions obtained by drawing n given straight lines.

PHP Code Editor:

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Previous: Print the number of combinations.
Next: Write a PHP program to test whether AB and CD are orthogonal or not.

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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
)