v0.40: Create exercises. Challenge the community.

lex_permutations

Your mission

Write a program that prints every permutation of one string argument.

See it in action

./lex_permutations cab | cat -e

Expected result

abc$
acb$
bac$
bca$
cab$
cba$

Your checklist

For your own tracking. Tests grade your code.

The program expects exactly one argument (argc must be 2).
Inputs contain no repeated characters.
Print one permutation per line.
The output must be in lexicographic order, even when the input argument is not sorted.
If the argument count is wrong, return 1.
Do not print duplicate lines.

More examples

./lex_permutations m | cat -e

Expected result

m$

Constraints

Expected files

lex_permutations.c

Allowed functions

writeputsmalloccallocreallocfree

lex_permutations

Recursion

Your mission

Write a program that prints every permutation of one string argument.

See it in action

./lex_permutations cab | cat -e

Expected result

abc$
acb$
bac$
bca$
cab$
cba$

Your checklist

For your own tracking. Tests grade your code.

The program expects exactly one argument (argc must be 2).
Inputs contain no repeated characters.
Print one permutation per line.
The output must be in lexicographic order, even when the input argument is not sorted.
If the argument count is wrong, return 1.
Do not print duplicate lines.

More examples

./lex_permutations m | cat -e

Expected result

m$

Constraints

Expected files

lex_permutations.c

Allowed functions

writeputsmalloccallocreallocfree

Tests

Run the tests to grade your code

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

Build

01Single characterWaiting

02Two characters in reverse orderWaiting

03Four distinct lettersWaiting

04Too many argumentsWaiting

05Missing argumentWaiting

06Unsorted three-letter inputWaiting

lex_permutations

Your mission

Write a program that prints every permutation of one string argument.

See it in action

./lex_permutations cab | cat -e

Expected result

abc$
acb$
bac$
bca$
cab$
cba$

Your checklist

For your own tracking. Tests grade your code.

The program expects exactly one argument (argc must be 2).
Inputs contain no repeated characters.
Print one permutation per line.
The output must be in lexicographic order, even when the input argument is not sorted.
If the argument count is wrong, return 1.
Do not print duplicate lines.

More examples

./lex_permutations m | cat -e

Expected result

m$

Constraints

Expected files

lex_permutations.c

Allowed functions

writeputsmalloccallocreallocfree

v0.40: Create exercises. Challenge the community.

Meet Studio →

lex_permutations

Recursion

Your mission

Write a program that prints every permutation of one string argument.

See it in action

./lex_permutations cab | cat -e

Expected result

abc$
acb$
bac$
bca$
cab$
cba$

Your checklist

For your own tracking. Tests grade your code.

The program expects exactly one argument (argc must be 2).
Inputs contain no repeated characters.
Print one permutation per line.
The output must be in lexicographic order, even when the input argument is not sorted.
If the argument count is wrong, return 1.
Do not print duplicate lines.

More examples

./lex_permutations m | cat -e

Expected result

m$

Constraints

Expected files

lex_permutations.c

Allowed functions

writeputsmalloccallocreallocfree

Tests

Run the tests to grade your code

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

Build

01Single characterWaiting

02Two characters in reverse orderWaiting

03Four distinct lettersWaiting

04Too many argumentsWaiting

05Missing argumentWaiting

06Unsorted three-letter inputWaiting