v0.40: Create exercises. Challenge the community.

find_any_char

Your mission

Implement a function that scans a string and returns the first position whose character appears in a second string.

See it in action

find_any_char("compile passed", "xyzp")

Expected result

pointer to `p`

Your checklist

For your own tracking. Tests grade your code.

The function receives two null-terminated strings: text and needles.
Walk through text from left to right.
Return a pointer to the first character in text that is also present anywhere in needles.
If no character matches, return NULL.
If needles is empty, return NULL.
Do not allocate memory and do not call library search functions.

More examples

find_any_char("branch", "aeiou")

Expected result

pointer to `a`

find_any_char("lint", "xyz")

Expected result

NULL

Constraints

Expected files

find_any_char.c

Allowed functions

None. Write every helper yourself.

Allowed headers

<stddef.h>defines NULL

find_any_char

Strings: walking and searching

Your mission

Implement a function that scans a string and returns the first position whose character appears in a second string.

See it in action

find_any_char("compile passed", "xyzp")

Expected result

pointer to `p`

Your checklist

For your own tracking. Tests grade your code.

The function receives two null-terminated strings: text and needles.
Walk through text from left to right.
Return a pointer to the first character in text that is also present anywhere in needles.
If no character matches, return NULL.
If needles is empty, return NULL.
Do not allocate memory and do not call library search functions.

More examples

find_any_char("branch", "aeiou")

Expected result

pointer to `a`

find_any_char("lint", "xyz")

Expected result

NULL

Constraints

Expected files

find_any_char.c

Allowed functions

None. Write every helper yourself.

Allowed headers

<stddef.h>defines NULL

Tests

Run the tests to grade your code

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

Build

01First matching characterWaiting

02First vowelWaiting

03No matching characterWaiting

04Empty source stringWaiting

05Empty search setWaiting

find_any_char

Your mission

Implement a function that scans a string and returns the first position whose character appears in a second string.

See it in action

find_any_char("compile passed", "xyzp")

Expected result

pointer to `p`

Your checklist

For your own tracking. Tests grade your code.

The function receives two null-terminated strings: text and needles.
Walk through text from left to right.
Return a pointer to the first character in text that is also present anywhere in needles.
If no character matches, return NULL.
If needles is empty, return NULL.
Do not allocate memory and do not call library search functions.

More examples

find_any_char("branch", "aeiou")

Expected result

pointer to `a`

find_any_char("lint", "xyz")

Expected result

NULL

Constraints

Expected files

find_any_char.c

Allowed functions

None. Write every helper yourself.

Allowed headers

<stddef.h>defines NULL

find_any_char

Strings: walking and searching

Your mission

Implement a function that scans a string and returns the first position whose character appears in a second string.

See it in action

find_any_char("compile passed", "xyzp")

Expected result

pointer to `p`

Your checklist

For your own tracking. Tests grade your code.

The function receives two null-terminated strings: text and needles.
Walk through text from left to right.
Return a pointer to the first character in text that is also present anywhere in needles.
If no character matches, return NULL.
If needles is empty, return NULL.
Do not allocate memory and do not call library search functions.

More examples

find_any_char("branch", "aeiou")

Expected result

pointer to `a`

find_any_char("lint", "xyz")

Expected result

NULL

Constraints

Expected files

find_any_char.c

Allowed functions

None. Write every helper yourself.

Allowed headers

<stddef.h>defines NULL

Tests

Run the tests to grade your code

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

Build

01First matching characterWaiting

02First vowelWaiting

03No matching characterWaiting

04Empty source stringWaiting

05Empty search setWaiting

v0.40: Create exercises. Challenge the community.

Meet Studio →