Question

Write a program that inputs a five-digit integer, separates the integer into its digits and prints them separated by three spaces each. [Hint: Use the integer division and modulus operators.] For example, if the user types in \(42339,\) the program should print:

Short answer

The program uses integer division and modulus to extract each digit from the five-digit number and prints them with three spaces in between.

Step-by-step solution

Prompt user for input

Start the program by asking the user to input a five-digit integer. Ensure the input is correctly formatted as an integer and has exactly five digits.

Extract each digit

Using integer division and modulus operations, separate the integer into its individual digits. For a given integer 'num', you can find the first digit by using 'num // 10000'. Subsequent digits can be found similarly by first taking the modulus of the number by the previous divisor, then using the appropriate divisor to extract each digit.

Print the digits

Once all five digits are extracted, print them out separated by three spaces. Ensure the output is formatted correctly according to the requirement.

Key concepts

Integer Division

One of the foundations of arithmetic operations in programming is integer division. In C++, when two integers are divided using the '/' operator, the result is automatically truncated, or rounded down, to the nearest integer. This means any fractional part of the result is disregarded. For example, if you divide 42339 by 10000 using integer division, the result is 4.

The operation is effectively used to isolate the higher-order digits of a multi-digit integer. In our example of a five-digit number, starting from the left, using successively smaller divisors by powers of 10, the five digits can be isolated in sequence using integer division. This is a key step in digit separation programs, as it allows us to extract each digit from a larger number for further processing or display.

Modulus Operator

After understanding integer division, the next critical concept is the modulus operator, often represented as '%'. This operator is used to find the remainder of the division of two integers. Unlike integer division, which gives the quotient, the modulus operator gives us the remainder left over.

For instance, if we take our previous example of 42339 and apply 42339 % 10000, the result is 2339. This operation is particularly useful when separating digits because it allows us to discard the digit(s) we have already processed (in this case, the first digit which is 4) and move on to the next. By strategically pairing integer division and the modulus operator, we can extract and remove each digit in turn, working our way through the entire integer.

C++ User Input

Collecting user input is a fundamental aspect of interactive programming. In C++, this is typically achieved with the use of cin, which stands for 'character input'. The cin object is used along with the extraction operator '>>' to direct the input entered by the user into a variable.

When designing a digit separation program like the one in our exercise, you would prompt the user to enter a five-digit integer, then use cin to read this value into an integer variable. It is important to ensure validity of the input, checking that it is an integer and within the expected range (10000 to 99999 for a five-digit number). Improper input handling could result in incorrect outcomes or program errors. Therefore, input validation is a crucial step in the operation of the program.