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variables_if_else_while

README.md

C - Variables, if, else, while

Resources

Read or watch

man or help

  • ascii (You do not need to learn about scanf, getc, getchar, EOF, EXIT_SUCCESS, time, rand, srand, RAND_MAX, for loops, do...while loops, functions.)

Learning Objectives

At the end of this project, you are expected to be able to explain to anyone, without the help of Google:

General

  • What are the arithmetic operators and how to use them
  • What are the logical operators (sometimes called boolean operators) and how to use them
  • What the the relational operators and how to use them
  • What values are considered TRUE and FALSE in C
  • What are the boolean operators and how to use them
  • How to use the if, if ... else statements
  • How to use comments
  • How to declare variables of types char, int, unsigned int
  • How to assign values to variables
  • How to print the values of variables of type char, int, unsigned int with printf
  • How to use the while loop
  • How to use variables with the while loop
  • How to print variables using printf
  • What is the ASCII character set
  • What are the purpose of the gcc flags -m32 and -m64

Requirements

General

Allowed editors: vi, vim, emacs All your files will be compiled on Ubuntu 20.04 LTS using gcc, using the options -Wall -Werror -Wextra -pedantic -std=gnu89 All your files should end with a new line A README.md file, at the root of the folder of the project There should be no errors and no warnings during compilation You are not allowed to use system Your code should use the Betty style. It will be checked using betty-style.pl and betty-doc.pl Quiz questions Great! You've completed the quiz successfully! Keep going! (Show quiz)

Tasks

0. Positive anything is better than negative nothing

This program will assign a random number to the variable n each time it is executed. Complete the source code in order to print whether the number stored in the variable n is positive or negative.

  • You can find the source code here
  • The variable n will store a different value every time you will run this program
  • You don’t have to understand what rand, srand, RAND_MAX do. Please do not touch this code
  • The output of the program should be:
    • The number, followed by
      • if the number is greater than 0: is positive
      • if the number is 0: is zero
      • if the number is less than 0: is negative
    • followed by a new line
root@ubuntu:~/$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 0-positive_or_negative.c -o 0-positive_or_negative
root@ubuntu:~/$ ./0-positive_or_negative
-520693284 is negative
root@ubuntu:~/$ ./0-positive_or_negative
-973398895 is negative
root@ubuntu:~/$ ./0-positive_or_negative
-199220452 is negative
root@ubuntu:~/$ ./0-positive_or_negative
561319348 is positive
root@ubuntu:~/$ ./0-positive_or_negative
561319348 is positive
root@ubuntu:~/$ ./0-positive_or_negative
266853958 is positive
root@ubuntu:~/$ ./0-positive_or_negative
-48147767 is negative
root@ubuntu:~/$ ./0-positive_or_negative
0 is zero
root@ubuntu:~/$

Repo :

1. The last digit

This program will assign a random number to the variable n each time it is executed. Complete the source code in order to print the last digit of the number stored in the variable n.

  • You can find the source code here
  • The variable n will store a different value every time you run this program
  • You don’t have to understand what rand, srand, and RAND_MAX do. Please do not touch this code
  • The output of the program should be:
    • The string Last digit of, followed by
    • n, followed by
    • the string is, followed by
      • if the last digit of n is greater than 5: the string and is greater than 5
      • if the last digit of n is 0: the string and is 0
      • if the last digit of n is less than 6 and not 0: the stringand is less than 6 and not 0
    • followed by a new line
root@ubuntu:~/$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 1-last_digit.c -o 1-last_digit
root@ubuntu:~/$ ./1-last_digit
Last digit of 629438752 is 2 and is less than 6 and not 0
root@ubuntu:~/$ ./1-last_digit
Last digit of -748255693 is -3 and is less than 6 and not 0
root@ubuntu:~/$ ./1-last_digit
Last digit of -1052791662 is -2 and is less than 6 and not 0
root@ubuntu:~/$ ./1-last_digit
Last digit of -284805734 is -4 and is less than 6 and not 0
root@ubuntu:~/$ ./1-last_digit
Last digit of -284805734 is -4 and is less than 6 and not 0
root@ubuntu:~/$ ./1-last_digit
Last digit of 491506926 is 6 and is greater than 5
root@ubuntu:~/$ ./1-last_digit
Last digit of 954249937 is 7 and is greater than 5
root@ubuntu:~/$ ./1-last_digit
Last digit of 652334952 is 2 and is less than 6 and not 0
root@ubuntu:~/$ ./1-last_digit
Last digit of -729688197 is -7 and is less than 6 and not 0
root@ubuntu:~/$ ./1-last_digit
Last digit of -729688197 is -7 and is less than 6 and not 0
root@ubuntu:~/$ ./1-last_digit
Last digit of 45528266 is 6 and is greater than 5
root@ubuntu:~/$ ./1-last_digit
Last digit of 45528266 is 6 and is greater than 5
root@ubuntu:~/$ ./1-last_digit
Last digit of 809065140 is 0 and is 0
root@ubuntu:~/0x01$

Repo :

2. I sometimes suffer from insomnia. And when I can't fall asleep, I play what I call the alphabet game

Write a program that prints the alphabet in lowercase, followed by a new line.

  • You can only use the putchar function (every other function (printf, puts, etc…) is forbidden)
  • All your code should be in the mainfunction
  • You can only use putchar twice in your code
root@ubuntu:~/$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 2-print_alphabet.c -o 2-print_alphabet
root@ubuntu:~/$ ./2-print_alphabet
abcdefghijklmnopqrstuvwxyz
root@ubuntu:~/0x01$

Repo :

3. alphABET

Write a program that prints the alphabet in lowercase, and then in uppercase, followed by a new line.

You can only use the putchar function (every other function (printf, puts, etc…) is forbidden) All your code should be in the main function You can only use putchar three times in your code

root@ubuntu:~/$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 3-print_alphabets.c -o 3-print_alphabets
root@ubuntu:~/$ ./3-print_alphabets | cat -e
abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$
root@ubuntu:~/0x01$

Repo :

4. When I was having that alphabet soup, I never thought that it would pay off

Write a program that prints the alphabet in lowercase, followed by a new line.

  • Print all the letters except q and e
  • You can only use the putchar function (every other function (printf, puts, etc…) is forbidden)
  • All your code should be in the main function
  • You can only use putchar twice in your code
root@ubuntu:~/$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 4-print_alphabet.c -o 4-print_alphabet
root@ubuntu:~/$ ./4-print_alphabet
abcdfghijklmnoprstuvwxyz
root@ubuntu:~/$ ./4-print_alphabet | grep [eq]
root@ubuntu:~/0x01$

Repo :

5. Numbers

Write a program that prints all single digit numbers of base 10 starting from 0, followed by a new line.

  • All your code should be in the main function
root@ubuntu:~/$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 5-print_numbers.c -o 5-print_numbers
root@ubuntu:~/$ ./5-print_numbers
0123456789
root@ubuntu:~/0x01$

Repo :

6. Numberz

Write a program that prints all single digit numbers of base 10 starting from 0, followed by a new line.

  • You are not allowed to use any variable of type char
  • You can only use the putchar function (every other function (printf, puts, etc…) is forbidden)
  • You can only use putchar twice in your code
  • All your code should be in the main function
root@ubuntu:~/$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 6-print_numberz.c -o 6-print_numberz
root@ubuntu:~/$ ./6-print_numberz
0123456789
root@ubuntu:~/0x01$

Repo :

7. Smile in the mirror

Write a program that prints the lowercase alphabet in reverse, followed by a new line.

  • You can only use the putchar function (every other function (printf, puts, etc…) is forbidden)
  • All your code should be in the main function
  • You can only use putchar twice in your code
root@ubuntu:~/$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 7-print_tebahpla.c -o 7-print_tebahpla
root@ubuntu:~/$ ./7-print_tebahpla
zyxwvutsrqponmlkjihgfedcba
root@ubuntu:~/0x01$

Repo :

8. Hexadecimal

Write a program that prints all the numbers of base 16 in lowercase, followed by a new line.

  • You can only use the putchar function (every other function (printf, puts, etc…) is forbidden)
  • All your code should be in the main function
  • You can only use putchar three times in your code
root@ubuntu:~/$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 8-print_base16.c -o 8-print_base16
root@ubuntu:~/$ ./8-print_base16
0123456789abcdef
root@ubuntu:~/0x01$

Repo :

9. Patience, persistence and perspiration make an unbeatable combination for success

Write a program that prints all possible combinations of single-digit numbers.

  • Numbers must be separated by ,, followed by a space
  • Numbers should be printed in ascending order
  • You can only use the putchar function (every other function (printf, puts, etc…) is forbidden)
  • All your code should be in the main function
  • You can only use putchar four times maximum in your code
  • You are not allowed to use any variable of type char
root@ubuntu:~/$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 9-print_comb.c -o 9-print_comb
root@ubuntu:~/$ ./9-print_comb | cat -e
0, 1, 2, 3, 4, 5, 6, 7, 8, 9$
root@ubuntu:~/0x01$

Repo :

Tasks #advanced

10. Inventing is a combination of brains and materials. The more brains you use, the less material you need

Write a program that prints all possible different combinations of two digits.

  • Numbers must be separated by ,, followed by a space
  • The two digits must be different
  • 01 and 10 are considered the same combination of the two digits 0 and 1
  • Print only the smallest combination of two digits
  • Numbers should be printed in ascending order, with two digits
  • You can only use the putchar function (every other function (printf, puts, etc…) is forbidden)
  • You can only use putchar five times maximum in your code
  • You are not allowed to use any variable of type char
  • All your code should be in the main function
root@ubuntu:~/$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 100-print_comb3.c -o 100-print_comb3
root@ubuntu:~/$ ./100-print_comb3
01, 02, 03, 04, 05, 06, 07, 08, 09, 12, 13, 14, 15, 16, 17, 18, 19, 23, 24, 25, 26, 27, 28, 29, 34, 35, 36, 37, 38, 39, 45, 46, 47, 48, 49, 56, 57, 58, 59, 67, 68, 69, 78, 79, 89
root@ubuntu:~/0x01$

Repo :

11. The success combination in business is: Do what you do better... and: do more of what you do...

Write a program that prints all possible different combinations of three digits.

  • Numbers must be separated by ,, followed by a space
  • The three digits must be different *012, 120, 102, 021, 201, 210 are considered the same combination of the three digits 0, 1 and 2
    • Print only the smallest combination of three digits
  • Numbers should be printed in ascending order, with three digits
  • You can only use the putchar function (every other function (printf, puts, etc…) is forbidden)
  • You can only use putchar six times maximum in your code
  • You are not allowed to use any variable of type char
  • All your code should be in the main function
root@ubuntu:~/$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 101-print_comb4.c -o 101-print_comb4
root@ubuntu:~/$ ./101-print_comb4
012, 013, 014, 015, 016, 017, 018, 019, 023, 024, 025, 026, 027, 028, 029, 034, 035, 036, 037, 038, 039, 045, 046, 047, 048, 049, 056, 057, 058, 059, 067, 068, 069, 078, 079, 089, 123, 124, 125, 126, 127, 128, 129, 134, 135, 136, 137, 138, 139, 145, 146, 147, 148, 149, 156, 157, 158, 159, 167, 168, 169, 178, 179, 189, 234, 235, 236, 237, 238, 239, 245, 246, 247, 248, 249, 256, 257, 258, 259, 267, 268, 269, 278, 279, 289, 345, 346, 347, 348, 349, 356, 357, 358, 359, 367, 368, 369, 378, 379, 389, 456, 457, 458, 459, 467, 468, 469, 478, 479, 489, 567, 568, 569, 578, 579, 589, 678, 679, 689, 789
root@ubuntu:~/0x01$

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12. Software is eating the World

Write a program that prints all possible combinations of two two-digit numbers.

  • The numbers should range from 0 to 99
  • The two numbers should be separated by a space
  • All numbers should be printed with two digits. 1 should be printed as 01
  • The combination of numbers must be separated by comma, followed by a space
  • The combinations of numbers should be printed in ascending order
    • 00 01 and 01 00 are considered as the same combination of the numbers 0 and 1
  • You can only use the putchar function (every other function (printf, puts, etc…) is forbidden)
  • You can only use putchar eight times maximum in your code
  • You are not allowed to use any variable of type char
  • All your code should be in the main function
root@ubuntu:~/$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 102-print_comb5.c -o 102-print_comb5
root@ubuntu:~/$ ./102-print_comb5
00 01, 00 02, 00 03, 00 04, 00 05, 00 06, 00 07, 00 08, 00 09, 00 10, 00 11, [...] 40 91, 40 92, 40 93, 40 94, 40 95, 40 96, 40 97, 40 98, 40 99, 41 42, 41 43, 41 44, 41 45, 41 46, 41 47, 41 48, 41 49, 41 50, 41 51, 41 52, 41 53 [...] 93 95, 93 96, 93 97, 93 98, 93 99, 94 95, 94 96, 94 97, 94 98, 94 99, 95 96, 95 97, 95 98, 95 99, 96 97, 96 98, 96 99, 97 98, 97 99, 98 99

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