Loops

1. Even numbers
   Write a program that prints all even numbers from (including) 10 to (including) 100. Each number should be printed on a separate line.
   Name the source file: even_numbers.c
2. Alphabet
   Write a program that prints all lower case characters from 'a' to 'z' on a single line without any separator. The program has to print one character at a time using a while loop. Print a newline (\n) character at the end of the sequence.
   Name the source file: alphabet.c
3. Sum of a Special Sequence
   Write a program that calculates the sum of all odd numbers greater than or equal to 50 and less than 1110 if the numbers can be divided by 3 without a remainder. Print the result to stdout.
   Once you have a working solution, consider if there is a better solution.
   Name the source file: special_sequence_sum.c
4. Faculty Function
   The faculty of an integral number is the product of all integral numbers between 1 and that number. For example, the faculty of 5 (usually written as 5! is 5 * 4 * 3 * 2 * 1. Write a program that calculates the faculty of 13 (13!) and prints the result to the terminal. Verify that your result is correct!
   Name the source file: faculty.c
5. Sum of Digits
   For many purposes it is useful to calculate the sum of the digits of a number. For example, the sum of the digits facilitates knowing whether or not a number can be divided by 3. Write a program that asks the user to input a number and calculates the sum of its digits. The sum of the digits has to be printed to stdout.
   A sample run of this program:

   Enter a number: 123
   The sum of the digits in 123 is 1 + 2 + 3 = 6.
   

   Name the source file: digit_sum.c
6. Sum of a Sequence of Numbers (more generic)
   Writing a program that always computes the same output has very limited utility. Based on your special_sequence_sum.c program write a new program that allows users to enter the lower limit (inclusive) and the upper limit (exclusive) of a sequence of numbers to be summed. Users also have to be able enter a number in case they only want every second / third / fourth / ... number to be summed up. That number has to default to 1. Print the result to stdout.
   Once you have a working solution, consider if there is a better solution.
   A sample run of this program:

   This programs computes the sum of a sequence of numbers.
   Enter the lower limit (inclusive): 123
   Enter the upper limit (exclusive): 456
   Only sum every nth number [default: 1 (every number)]: 100
   The desired sum is 1092.
   

   Note that 1092 is the sum of 123 + 223 + 323 + 423.
   Name the source file: sequence_sum.c