v0.40: Create exercises. Challenge the community.

words_back

Your mission

Write a program that takes a single string argument and prints its words in reverse order.

See it in action

./words_back "hello world"

Expected result

world hello

Your checklist

For your own tracking. Tests grade your code.

Words are separated by spaces or tabs.
Inputs are well-formed: no leading or trailing separators, and no consecutive separators between words.
Output the reversed word sequence separated by single spaces, followed by a newline.
If the program does not receive exactly one argument (argc must be 2), print wrong number of arguments followed by a newline.
You may use write, malloc, and free.

More examples

./words_back "one two three four"

Expected result

four three two one

./words_back

Expected result

wrong number of arguments

Constraints

Expected files

words_back.c

Allowed functions

writemallocfree

Allowed headers

<stdlib.h>declares malloc and free

<unistd.h>declares write

words_back

Words and tokens

Your mission

Write a program that takes a single string argument and prints its words in reverse order.

See it in action

./words_back "hello world"

Expected result

world hello

Your checklist

For your own tracking. Tests grade your code.

Words are separated by spaces or tabs.
Inputs are well-formed: no leading or trailing separators, and no consecutive separators between words.
Output the reversed word sequence separated by single spaces, followed by a newline.
If the program does not receive exactly one argument (argc must be 2), print wrong number of arguments followed by a newline.
You may use write, malloc, and free.

More examples

./words_back "one two three four"

Expected result

four three two one

./words_back

Expected result

wrong number of arguments

Constraints

Expected files

words_back.c

Allowed functions

writemallocfree

Allowed headers

<stdlib.h>declares malloc and free

<unistd.h>declares write

Tests

Run the tests to grade your code

Build your code, then check each test here. Open a result to inspect its output.

Build

01No argumentsWaiting

02Five words reversedWaiting

03Four words reversedWaiting

04Two words reversedWaiting

05Single word unchangedWaiting

words_back

Your mission

Write a program that takes a single string argument and prints its words in reverse order.

See it in action

./words_back "hello world"

Expected result

world hello

Your checklist

For your own tracking. Tests grade your code.

Words are separated by spaces or tabs.
Inputs are well-formed: no leading or trailing separators, and no consecutive separators between words.
Output the reversed word sequence separated by single spaces, followed by a newline.
If the program does not receive exactly one argument (argc must be 2), print wrong number of arguments followed by a newline.
You may use write, malloc, and free.

More examples

./words_back "one two three four"

Expected result

four three two one

./words_back

Expected result

wrong number of arguments

Constraints

Expected files

words_back.c

Allowed functions

writemallocfree

Allowed headers

<stdlib.h>declares malloc and free

<unistd.h>declares write

v0.40: Create exercises. Challenge the community.

Meet Studio →

words_back

Words and tokens

Your mission

Write a program that takes a single string argument and prints its words in reverse order.

See it in action

./words_back "hello world"

Expected result

world hello

Your checklist

For your own tracking. Tests grade your code.

Words are separated by spaces or tabs.
Inputs are well-formed: no leading or trailing separators, and no consecutive separators between words.
Output the reversed word sequence separated by single spaces, followed by a newline.
If the program does not receive exactly one argument (argc must be 2), print wrong number of arguments followed by a newline.
You may use write, malloc, and free.

More examples

./words_back "one two three four"

Expected result

four three two one

./words_back

Expected result

wrong number of arguments

Constraints

Expected files

words_back.c

Allowed functions

writemallocfree

Allowed headers

<stdlib.h>declares malloc and free

<unistd.h>declares write

Tests

Run the tests to grade your code

Build your code, then check each test here. Open a result to inspect its output.

Build

01No argumentsWaiting

02Five words reversedWaiting

03Four words reversedWaiting

04Two words reversedWaiting

05Single word unchangedWaiting