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

Last update on April 19 2025 11:49:32 (UTC/GMT +8 hours)

47. Digit Count of Sum

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:

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

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:

For more Practice: Solve these Related Problems:

Write a PHP script to sum two integers and then count the number of digits in the resulting total.
Write a PHP function that computes the sum of two numbers and returns the number of digits using string length.
Write a PHP script to sum large integers and determine the digit count without explicit type conversion.
Write a PHP script to calculate the sum and iteratively determine the count of digits in the result.

PHP Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous: Write a PHP program to find heights of the top three building in descending order from eight given buildings.
Next: Write a PHP program to check whether three given lengths (integers) of three sides form a right triangle. Print "Yes" if the given sides form a right triangle otherwise print "No".