PHP Exercises: Find the difference between the largest integer and the smallest integer

Last update on May 27 2025 13:08:38 (UTC/GMT +8 hours)

64. Difference Between Largest and Smallest Integer Formed

Write a PHP program to find the difference between the largest integer and the smallest integer which are created by 8 numbers from 0 to 9. The number that can be rearranged shall start with 0 as in 00135668.

Input: The difference between the largest integer and the smallest integer.

Pictorial Presentation:

PHP: Find the difference between the largest integer and the smallest integer.

Sample Solution:

PHP Code:

<?php
// Read the number of test cases from standard input
fscanf(STDIN, '%d', $n);

// Loop through each test case
for ($i = 0; $i < $n; $i++) {
    // Read the string from standard input
    fscanf(STDIN, '%s', $s);

    // Convert the string to an array of characters
    $s = str_split($s);

    // Sort the array of characters in descending order
    rsort($s);

    // Convert the sorted array back to an integer to get the largest number
    $a = (int) implode('', $s);

    // Sort the array of characters in ascending order
    sort($s);

    // Convert the sorted array back to an integer to get the smallest number
    $b = (int) implode('', $s);

    // Output the difference between the largest and smallest integers
    echo "Difference between the largest integer and the smallest integer:\n";
    echo $a - $b;
    echo PHP_EOL;
}

?>

Explanation:

Read Number of Test Cases:

The code reads an integer input from standard input, representing the number of test cases (fscanf(STDIN, '%d', $n)).

Loop Through Test Cases:

A for loop iterates through each test case from 0 to n-1.

Read Input String:

For each test case, it reads a string input (fscanf(STDIN, '%s', $s)).

Convert String to Array:

The string is converted into an array of characters using str_split($s).

Sort Characters in Descending Order:

The character array is sorted in descending order using rsort($s).

Create Largest Number:

The sorted array is joined back into a string with implode('', $s) and then converted to an integer, representing the largest number ($a).

Sort Characters in Ascending Order:

The character array is sorted in ascending order using sort($s).

Create Smallest Number:

The sorted array is joined back into a string and converted to an integer, representing the smallest number ($b).

Calculate and Output Difference:

The code calculates the difference between the largest and smallest integers ($a - $b) and outputs the result, preceded by a descriptive message.

Sample Input:
1
34568729

Sample Output:

Difference between the largest integer and the smallest integer:
75308643

Flowchart:

For more Practice: Solve these Related Problems:

Write a PHP script to rearrange given digits into the largest possible integer and the smallest possible integer.
Write a PHP function to calculate the difference between the maximum and minimum numbers formed from a set of digits.
Write a PHP script to form extreme values from provided digits and subtract the smaller from the larger.
Write a PHP script to rearrange digits in ascending and descending order and compute the numerical difference.

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PHP Code Editor:

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