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

Last update on May 27 2025 13:09:23 (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:

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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