PHP Exercises: Compute the digit number of sum of two given integers

Last update on December 20 2024 10:18:01 (UTC/GMT +8 hours)

Write a PHP program to compute the digit number of sum of two given integers.

Input:
Each test case consists of two non-negative integers x and y which are separated by a space in a line.
0 ≤ x, y ≤ 1,000,000

Pictorial Presentation:

Sample Solution:

PHP Code:

<?php
// Infinite loop to continuously read input from STDIN
while (true) {
    // Read and split the input line into an array of strings
    $inputs = explode(' ', trim(fgets(STDIN))); 

    // Check if the input is not an array or has fewer than 2 elements
    if (!is_array($inputs) || count($inputs) < 2) {
        exit; // Exit the program if conditions are met
    }

    // Extract the first and second elements from the input array
    $a = $inputs[0];
    $b = $inputs[1]; 

    // Call the numDigits function to calculate the number of digits in the sum
    $d = numDigits($a + $b);

    // Print the result with a descriptive message
    echo("Digit number of sum of two given integers: ");
    echo $d . "\n";
} 

// Function to calculate the number of digits in a given number
function numDigits($n) {
    return (int)(log10($n) + 1);
}

?>

Explanation:

• Infinite Loop:
• The code contains a while (true) loop that runs indefinitely to continuously read input from the user.
• Reading Input:
• Inside the loop, it reads a line from standard input (STDIN) using fgets(STDIN).
• The line is trimmed of whitespace and split into an array of strings using explode(' ', trim(...)).
• Input Validation:
• The code checks if the input is not an array or if it has fewer than two elements (count($inputs) < 2).
• If this condition is met, the program exits using exit.
• Extracting Values:
• The first and second elements of the input array are assigned to variables $a and $b, respectively.
• Calculating the Number of Digits:
• The code calls the numDigits function, passing the sum of $a and $b as an argument, to calculate the number of digits in the result.
• Printing the Result:
• It prints a message indicating that it will show the number of digits in the sum.
• The result ($d, the number of digits) is printed.
• Function Definition:
• The numDigits function calculates the number of digits in a given number $n.
• It uses the formula (int)(log10($n) + 1), which calculates the logarithm base 10 of $n to determine the number of digits.

Output:

Digit number of sum of two given integers: 2

Flowchart:

PHP Code Editor:

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