Concepts

For this project, we expect you to look at this concept:

Struggling with the sandbox? Try this: Using Docker & WSL on your local host

Resources

Read or watch:

Everything you need to know to start with C.pdf (You do not have to learn everything in there yet, but make sure you read it entirely first and make sure you understand the slides: “comments”, “Data types | Integer types”, “Declaration”, “Characters”, “Arithmetic operators”, “Variables assignments”, “Comparisons”, “Logical operators”, “if, if…else”, “while loops”.)
Keywords and identifiers
integers
Arithmetic Operators in C
If statements in C
if…else statement
Relational operators
Logical operators
while loop in C
While loop

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.)

Additional resources

Introduction to C (Basic structure and variables)

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

Question #0

What is the size of the unsigned int data type?

8 bytes
1 byte
2 bytes
4 bytes

Question #1

Which of the following are valid if statements in ANSI C and Betty-compliant? (Considering a and b two variables of type int)

Please select all correct answers

if (a > b)
  return (a);

if a > b
{
  return (a);
}

if (a > b)
{
  return (a);
}

if ((((((a > b))))))
{
  return (a);
}

if {a > b}
(
  return {a};
)

Question #2

What is the size of the char data type?

8 bytes
1 byte
2 bytes
4 bytes

Question #3

What is the size of the float data type?

8 bytes
1 byte
2 bytes
4 bytes

Question #4

Which of the following are valid for statements in ANSI C and Betty-compliant? (Considering a and b two variables of type int)

Please select all correct answers

a = 0;
for (; a < b;)
{
    printf("%d\n", a++);
}

for (a = 0; a < b; a++)
{
    printf("%d\n", a);
}

for (a = 0; a < b; a++)
    printf("%d\n", a);

a = 0;
for (a < b;;)
{
    printf("%d\n", a++);
}

for (int a = 0; a < b; a++)
{
    printf("%d\n", a);
}

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

julien@ubuntu:~/0x01$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 0-positive_or_negative.c -o 0-positive_or_negative
julien@ubuntu:~/0x01$ ./0-positive_or_negative
-520693284 is negative
julien@ubuntu:~/0x01$ ./0-positive_or_negative
-973398895 is negative
julien@ubuntu:~/0x01$ ./0-positive_or_negative
-199220452 is negative
julien@ubuntu:~/0x01$ ./0-positive_or_negative
561319348 is positive
julien@ubuntu:~/0x01$ ./0-positive_or_negative
561319348 is positive
julien@ubuntu:~/0x01$ ./0-positive_or_negative
266853958 is positive
julien@ubuntu:~/0x01$ ./0-positive_or_negative
-48147767 is negative
julien@ubuntu:~/0x01$ ./0-positive_or_negative
0 is zero
julien@ubuntu:~/0x01$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x01-variables_if_else_while
File: 0-positive_or_negative.c

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 string and is less than 6 and not 0
- followed by a new line

julien@ubuntu:~/0x01$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 1-last_digit.c -o 1-last_digit
julien@ubuntu:~/0x01$ ./1-last_digit
Last digit of 629438752 is 2 and is less than 6 and not 0
julien@ubuntu:~/0x01$ ./1-last_digit
Last digit of -748255693 is -3 and is less than 6 and not 0
julien@ubuntu:~/0x01$ ./1-last_digit
Last digit of -1052791662 is -2 and is less than 6 and not 0
julien@ubuntu:~/0x01$ ./1-last_digit
Last digit of -284805734 is -4 and is less than 6 and not 0
julien@ubuntu:~/0x01$ ./1-last_digit
Last digit of -284805734 is -4 and is less than 6 and not 0
julien@ubuntu:~/0x01$ ./1-last_digit
Last digit of 491506926 is 6 and is greater than 5
julien@ubuntu:~/0x01$ ./1-last_digit
Last digit of 954249937 is 7 and is greater than 5
julien@ubuntu:~/0x01$ ./1-last_digit
Last digit of 652334952 is 2 and is less than 6 and not 0
julien@ubuntu:~/0x01$ ./1-last_digit
Last digit of -729688197 is -7 and is less than 6 and not 0
julien@ubuntu:~/0x01$ ./1-last_digit
Last digit of -729688197 is -7 and is less than 6 and not 0
julien@ubuntu:~/0x01$ ./1-last_digit
Last digit of 45528266 is 6 and is greater than 5
julien@ubuntu:~/0x01$ ./1-last_digit
Last digit of 45528266 is 6 and is greater than 5
julien@ubuntu:~/0x01$ ./1-last_digit
Last digit of 809065140 is 0 and is 0
julien@ubuntu:~/0x01$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x01-variables_if_else_while
File: 1-last_digit.c

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 main function
You can only use putchar twice in your code

julien@ubuntu:~/0x01$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 2-print_alphabet.c -o 2-print_alphabet
julien@ubuntu:~/0x01$ ./2-print_alphabet
abcdefghijklmnopqrstuvwxyz
julien@ubuntu:~/0x01$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x01-variables_if_else_while
File: 2-print_alphabet.c

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

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

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x01-variables_if_else_while
File: 3-print_alphabets.c

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

julien@ubuntu:~/0x01$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 4-print_alphabt.c -o 4-print_alphabt
julien@ubuntu:~/0x01$ ./4-print_alphabt
abcdfghijklmnoprstuvwxyz
julien@ubuntu:~/0x01$ ./4-print_alphabt | grep [eq]
julien@ubuntu:~/0x01$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x01-variables_if_else_while
File: 4-print_alphabt.c

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

julien@ubuntu:~/0x01$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 5-print_numbers.c -o 5-print_numbers
julien@ubuntu:~/0x01$ ./5-print_numbers
0123456789
julien@ubuntu:~/0x01$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x01-variables_if_else_while
File: 5-print_numbers.c

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

julien@ubuntu:~/0x01$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 6-print_numberz.c -o 6-print_numberz
julien@ubuntu:~/0x01$ ./6-print_numberz
0123456789
julien@ubuntu:~/0x01$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x01-variables_if_else_while
File: 6-print_numberz.c

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

julien@ubuntu:~/0x01$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 7-print_tebahpla.c -o 7-print_tebahpla
julien@ubuntu:~/0x01$ ./7-print_tebahpla
zyxwvutsrqponmlkjihgfedcba
julien@ubuntu:~/0x01$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x01-variables_if_else_while
File: 7-print_tebahpla.c

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

julien@ubuntu:~/0x01$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 8-print_base16.c -o 8-print_base16
julien@ubuntu:~/0x01$ ./8-print_base16
0123456789abcdef
julien@ubuntu:~/0x01$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x01-variables_if_else_while
File: 8-print_base16.c

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

julien@ubuntu:~/0x01$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 9-print_comb.c -o 9-print_comb
julien@ubuntu:~/0x01$ ./9-print_comb | cat -e
0, 1, 2, 3, 4, 5, 6, 7, 8, 9$
julien@ubuntu:~/0x01$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x01-variables_if_else_while
File: 9-print_comb.c

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

julien@ubuntu:~/0x01$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 100-print_comb3.c -o 100-print_comb3
julien@ubuntu:~/0x01$ ./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
julien@ubuntu:~/0x01$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x01-variables_if_else_while
File: 100-print_comb3.c

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

julien@ubuntu:~/0x01$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 101-print_comb4.c -o 101-print_comb4
julien@ubuntu:~/0x01$ ./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
julien@ubuntu:~/0x01$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x01-variables_if_else_while
File: 101-print_comb4.c

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

julien@ubuntu:~/0x01$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 102-print_comb5.c -o 102-print_comb5
julien@ubuntu:~/0x01$ ./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

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x01-variables_if_else_while
File: 102-print_comb5.c

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

README.md

README.md

Concepts

Resources

Additional resources

Learning Objectives

General

Requirements

General

Quiz questions

Question #0

Question #1

Question #2

Question #3

Question #4

Tasks

0. Positive anything is better than negative nothing

1. The last digit

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

3. alphABET

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

5. Numbers

6. Numberz

7. Smile in the mirror

8. Hexadecimal

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

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

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

12. Software is eating the World

Files

README.md

Latest commit

History

README.md

File metadata and controls

Concepts

Resources

Additional resources

Learning Objectives

General

Requirements

General

Quiz questions

Question #0

Question #1

Question #2

Question #3

Question #4

Tasks

0. Positive anything is better than negative nothing

1. The last digit

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

3. alphABET

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

5. Numbers

6. Numberz

7. Smile in the mirror

8. Hexadecimal

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

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

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

12. Software is eating the World