Some nice tricks you all should know:
// #1 - the modulo operator (just a reminder):
int x = 125;
int y = 7;
int z = 5;
int divisionRemainder = x % y; // 6
divisionRemainder = x % z; // 0
// #2 - how to get the last digit of a number:
int number = 12345;
int lastDigit = number % 10; // 5
// #3 - how to omit the last digit of a number:
int number2 = 12345;
int shorterNumber = number2 / 10; // 1234
And now, let's write down some code!
Exercise #1
Write a program which gets a number from the user and prints the sum of its digits. For example:
Enter a number:
123
The sum of the digits of the number 123 is 6
(Hint: use the tricks above).
Exercise #2
Write a program which gets an integer number from the user and checks if it's a prime number. If it's a prime number the program prints "Prime", and otherwise it prints "Not prime". (Hint: A number is prime if it is not divisible by any smaller number). For example:
Enter a number:
9
Not prime
Enter a number:
3
Prime
Exercise #3
Write a program which gets from the user an integer and builds a pyramid of asterisks ('*') with a base of this size. For example:
Insert the base size of the pyramid:
5
*
***
*****
Insert the base size of the pyramid:
6
**
****
******
Insert the base size of the pyramid
25
*
***
*****
*******
*********
***********
*************
***************
*****************
*******************
*********************
***********************
*************************
Pay attention that if the base size is an even number, the head of the pyramid should be "**" and not '*'.
Good luck!
Always remember, it's much C-mpler than you thought!
Regards,
Gilad
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