v0.40: Create exercises. Challenge the community.

char_merge

Your mission

Write a program that receives two strings and prints every unique character that appears in either one, without any duplicates. Output order is driven by the second string first, then any remaining characters from the first string.

See it in action

./char_merge "rebase" "stdin never lies" | cat -e

Expected result

stdin evrlba$

Your checklist

For your own tracking. Tests grade your code.

The program expects exactly two arguments.
If the program does not receive exactly two arguments (argc must be 3), print wrong number of arguments followed by a newline.
Traverse the second string and print each character the first time it is seen.
Then traverse the first string and print each character that has not already been printed.
Each character must appear at most once in the output.
End the output with a newline.

More examples

./char_merge "grep found nothing" "exit" | cat -e

Expected result

exitgrp foundh$

./char_merge | cat -e

Expected result

wrong number of arguments$

Constraints

Expected files

char_merge.c

Allowed functions

write

char_merge

Transforming text

Your mission

See it in action

./char_merge "rebase" "stdin never lies" | cat -e

Expected result

stdin evrlba$

Your checklist

For your own tracking. Tests grade your code.

The program expects exactly two arguments.
If the program does not receive exactly two arguments (argc must be 3), print wrong number of arguments followed by a newline.
Traverse the second string and print each character the first time it is seen.
Then traverse the first string and print each character that has not already been printed.
Each character must appear at most once in the output.
End the output with a newline.

More examples

./char_merge "grep found nothing" "exit" | cat -e

Expected result

exitgrp foundh$

./char_merge | cat -e

Expected result

wrong number of arguments$

Constraints

Expected files

char_merge.c

Allowed functions

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

02Only one argumentWaiting

03Order from second stringWaiting

04Dev culture stringWaiting

05Identical stringsWaiting

06Empty second stringWaiting

07Empty first stringWaiting

char_merge

Your mission

See it in action

./char_merge "rebase" "stdin never lies" | cat -e

Expected result

stdin evrlba$

Your checklist

For your own tracking. Tests grade your code.

The program expects exactly two arguments.
If the program does not receive exactly two arguments (argc must be 3), print wrong number of arguments followed by a newline.
Traverse the second string and print each character the first time it is seen.
Then traverse the first string and print each character that has not already been printed.
Each character must appear at most once in the output.
End the output with a newline.

More examples

./char_merge "grep found nothing" "exit" | cat -e

Expected result

exitgrp foundh$

./char_merge | cat -e

Expected result

wrong number of arguments$

Constraints

Expected files

char_merge.c

Allowed functions

write

v0.40: Create exercises. Challenge the community.

Meet Studio →

char_merge

Transforming text

Your mission

See it in action

./char_merge "rebase" "stdin never lies" | cat -e

Expected result

stdin evrlba$

Your checklist

For your own tracking. Tests grade your code.

The program expects exactly two arguments.
If the program does not receive exactly two arguments (argc must be 3), print wrong number of arguments followed by a newline.
Traverse the second string and print each character the first time it is seen.
Then traverse the first string and print each character that has not already been printed.
Each character must appear at most once in the output.
End the output with a newline.

More examples

./char_merge "grep found nothing" "exit" | cat -e

Expected result

exitgrp foundh$

./char_merge | cat -e

Expected result

wrong number of arguments$

Constraints

Expected files

char_merge.c

Allowed functions

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

02Only one argumentWaiting

03Order from second stringWaiting

04Dev culture stringWaiting

05Identical stringsWaiting

06Empty second stringWaiting

07Empty first stringWaiting