PHP Exercises: Find heights of the top three building in descending order from eight given buildings

PHP: Exercise-46 with Solution

Write a PHP program to find heights of the top three building in descending order from eight given buildings.

Input:
0 ≤ height of building (integer) ≤ 10,000

Pictorial Presentation:

Sample Solution:

PHP Code:

<?php
// Create an empty array to store building heights
$heights = array();

// Read input from STDIN until end-of-file
while ($line = fgets(STDIN)) {
    // Remove newline characters and convert to integer, then push to the heights array
    rtrim($line, "\n");
    array_push($heights, (int)$line);
}

// Sort the heights array in descending order
rsort($heights);

// Print the top three building heights
print("Heights of the top three buildings:\n");
echo $heights[0]."\n"; // Print the height of the tallest building
echo $heights[1]."\n"; // Print the height of the second tallest building
echo $heights[2]."\n"; // Print the height of the third tallest building

?>

Explanation:

• Array Initialization:
• An empty array called $heights is created to store the heights of buildings.
• Reading Input:
• A while loop is used to read input from the standard input (STDIN) line by line until the end-of-file (EOF) is reached.
• fgets(STDIN) reads a line of input.
• Processing Input:
• Each line is processed to remove any trailing newline characters using rtrim($line, "\n").
• The line is then converted to an integer using (int)$line and pushed into the $heights array using array_push().
• Sorting Heights:
• The rsort($heights) function sorts the $heights array in descending order, meaning the tallest buildings will appear first.
• Output Top Three Heights:
• A message is printed to indicate that the top three building heights will be displayed.
• The first three elements of the sorted $heights array (i.e., the tallest, second tallest, and third tallest buildings) are printed using echo.
• Prints:
• echo $heights[0]."\n" prints the height of the tallest building.
• echo $heights[1]."\n" prints the height of the second tallest building.
• echo $heights[2]."\n" prints the height of the third tallest building.

Output:

Heights of the top three buildings:
45
25
24

Flowchart:

PHP Code Editor:

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