PHP Exercises: Compute and print sum of two given integers

PHP: Exercise-54 with Solution

Write a PHP program to compute and print sum of two given integers (more than or equal to zero). If given integers or the sum have more than 80 digits, print "overflow".

Pictorial Presentation:

Sample Solution:

PHP Code:

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

// Loop through each test case
for ($i = 0; $i < $N; $i++) {
    // Read two numbers as strings
    fscanf(STDIN, '%s', $a);
    fscanf(STDIN, '%s', $b);

    // Check if the length of either number is greater than 80
    if (max(strlen($a), strlen($b)) > 80) {
        echo "overflow\n";
        continue; // Skip to the next iteration if overflow occurs
    }

    // Initialize an array to store the result
    $arr = array_fill(0, 81, 0);

    // Pad the numbers with leading zeros to make them of length 81
    $a = sprintf('%081s', $a);
    $b = sprintf('%081s', $b);

    // Perform addition of the two numbers
    for ($j = 80; $j > 0; $j--) {
        $n = $arr[$j] + $a[$j] + $b[$j];

        // Check for carry
        if ($n >= 10) {
            $arr[$j] = substr($n, 1);
            $arr[$j - 1] += 1;
        } else {
            $arr[$j] = $n;
        }
    }

    // Remove leading zeros and check for overflow
    $result = preg_replace('/^0+(\d+)$/', '$1', implode('', $arr));

    // Output the result or indicate overflow
    if (strlen($result) > 80) {
        echo "overflow\n";
    } else {
        echo $result, PHP_EOL;
    }
}

?>

Sample Output:

46
overflow
overflow
overflow
overflow
...
overflow
overflow
overflow

Flowchart:

PHP Code Editor:

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