# Robson ▸ Little Red Book ▸ Arithmetic

## Chapter 1 - Question 1

Given two integers, output their sum, difference and product.

### Solution 1

PHP:

`<?` `    // two integers, these can be any numbers` `    // the numbers are randomly generated to add some variety` `    // mt_rand() is a faster version of rand()` `    \$a = mt_rand(1, 10);` `    \$b = mt_rand(1, 10);` ` ` `    // show what the numbers are` `    echo \$a . ' and ' . \$b . '<br /> <br />';` `    // first, output their sum` `    echo 'Sum: ' . (\$a + \$b) . '<br />';` `    // second, output the difference` `    // abs() is used in case the second number is greater than the first` `    echo 'Difference: ' . abs(\$a - \$b) . '<br />';` `    // finally, output the product` `    echo 'Product: ' . (\$a * \$b);` `?>    `

Which produces:

8 and 7

Sum: 15
Difference: 1
Product: 56

### Solution 2

C++:

`#include <stdio.h>` `#include <stdlib.h>` ` ` `int main ()` `{` `    int num1, num2;` `    ` `    printf("Enter a number\n>");` `    scanf("%d", &num1);` `    printf("Enter another number\n>");` `    scanf("%d", &num2);` `    ` `    printf("Sum: %d", num1 + num2);` `    printf("\nDifference: %d", abs(num1 - num2));` `    printf("\nProduct: %d", num1 * num2);` ` ` `    return 0;` `}`

### Solution 3

I've written another C++ solution now that I know a little bit more about the language. This uses more compact code and arguments sent by the user when running the program.

Example usage:

`C:\code>arithmetic 9 2Sum: 11Difference: 7Product: 18C:\code>`
`#include <stdio.h>` `#include <stdlib.h>` ` ` `using namespace std;` ` ` `int main(int argc, char *argv[])` `{` `    int n1 = atoi(argv), n2 = atoi(argv);` `    printf("Sum: %d\nDifference: %d\nProduct: %d", n1 + n2, abs(n1 - n2), n1 * n2);` `}`

## Log

• May 9, 2005 - Added solution 3.
• Apr 21, 2005 - Added solution 2.
• Jan 30, 2005 - Added solution 1.
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