v0.40: Create exercises. Challenge the community.

ranges_overlap

Your mission

Write a function that returns 1 when two byte slices taken from the same array share at least one byte, and 0 when they do not.

See it in action

ranges_overlap(buf, 6, buf + 4, 6)

Expected result

Your checklist

For your own tracking. Tests grade your code.

a and na describe the first slice: na bytes starting at the address a. b and nb describe the second slice the same way.
Both slices always come from the same array, which is what makes comparing a and b with < or > defined behavior in C. Comparing pointers into two unrelated allocations is not.
Return 1 when at least one byte belongs to both slices. Return 0 otherwise.
Two slices that merely touch do not overlap: if one ends exactly where the other starts, the answer is 0.
A slice of length 0 covers no byte, so it overlaps nothing. Return 0 as soon as na or nb is 0, whatever the addresses are.
Never read the bytes themselves. The answer depends only on the two addresses and the two lengths.
In the examples, buf is a char buf[16] and every slice is cut out of it.

More examples

ranges_overlap(buf, 4, buf + 4, 4)

Expected result

ranges_overlap(buf, 0, buf, 8)

Expected result

Constraints

Expected files

ranges_overlap.c

Allowed functions

None. Write every helper yourself.

Allowed headers

<stddef.h>defines size_t

ranges_overlap

Pointers

Your mission

Write a function that returns 1 when two byte slices taken from the same array share at least one byte, and 0 when they do not.

See it in action

ranges_overlap(buf, 6, buf + 4, 6)

Expected result

Your checklist

For your own tracking. Tests grade your code.

a and na describe the first slice: na bytes starting at the address a. b and nb describe the second slice the same way.
Both slices always come from the same array, which is what makes comparing a and b with < or > defined behavior in C. Comparing pointers into two unrelated allocations is not.
Return 1 when at least one byte belongs to both slices. Return 0 otherwise.
Two slices that merely touch do not overlap: if one ends exactly where the other starts, the answer is 0.
A slice of length 0 covers no byte, so it overlaps nothing. Return 0 as soon as na or nb is 0, whatever the addresses are.
Never read the bytes themselves. The answer depends only on the two addresses and the two lengths.
In the examples, buf is a char buf[16] and every slice is cut out of it.

More examples

ranges_overlap(buf, 4, buf + 4, 4)

Expected result

ranges_overlap(buf, 0, buf, 8)

Expected result

Constraints

Expected files

ranges_overlap.c

Allowed functions

None. Write every helper yourself.

Allowed headers

<stddef.h>defines size_t

Tests

Run the tests to grade your code

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

Build

01Slices far apartWaiting

02First slice ends where the second startsWaiting

03Second slice ends where the first startsWaiting

04Tail of the first slice covers the head of the secondWaiting

05Head of the first slice covers the tail of the secondWaiting

06Same address and same lengthWaiting

07Second slice sits inside the firstWaiting

08First slice sits inside the secondWaiting

09Exactly one shared byte, first slice aheadWaiting

10Exactly one shared byte, second slice aheadWaiting

11Same start, one byte against nineWaiting

12Whole array against its last byteWaiting

13Last byte against everything before itWaiting

14na is zeroWaiting

15nb is zeroWaiting

16Both lengths are zeroWaiting

17Empty slice placed inside a real oneWaiting

ranges_overlap

Your mission

Write a function that returns 1 when two byte slices taken from the same array share at least one byte, and 0 when they do not.

See it in action

ranges_overlap(buf, 6, buf + 4, 6)

Expected result

Your checklist

For your own tracking. Tests grade your code.

a and na describe the first slice: na bytes starting at the address a. b and nb describe the second slice the same way.
Both slices always come from the same array, which is what makes comparing a and b with < or > defined behavior in C. Comparing pointers into two unrelated allocations is not.
Return 1 when at least one byte belongs to both slices. Return 0 otherwise.
Two slices that merely touch do not overlap: if one ends exactly where the other starts, the answer is 0.
A slice of length 0 covers no byte, so it overlaps nothing. Return 0 as soon as na or nb is 0, whatever the addresses are.
Never read the bytes themselves. The answer depends only on the two addresses and the two lengths.
In the examples, buf is a char buf[16] and every slice is cut out of it.

More examples

ranges_overlap(buf, 4, buf + 4, 4)

Expected result

ranges_overlap(buf, 0, buf, 8)

Expected result

Constraints

Expected files

ranges_overlap.c

Allowed functions

None. Write every helper yourself.

Allowed headers

<stddef.h>defines size_t

v0.40: Create exercises. Challenge the community.

Meet Studio →

ranges_overlap

Pointers

Your mission

Write a function that returns 1 when two byte slices taken from the same array share at least one byte, and 0 when they do not.

See it in action

ranges_overlap(buf, 6, buf + 4, 6)

Expected result

Your checklist

For your own tracking. Tests grade your code.

a and na describe the first slice: na bytes starting at the address a. b and nb describe the second slice the same way.
Both slices always come from the same array, which is what makes comparing a and b with < or > defined behavior in C. Comparing pointers into two unrelated allocations is not.
Return 1 when at least one byte belongs to both slices. Return 0 otherwise.
Two slices that merely touch do not overlap: if one ends exactly where the other starts, the answer is 0.
A slice of length 0 covers no byte, so it overlaps nothing. Return 0 as soon as na or nb is 0, whatever the addresses are.
Never read the bytes themselves. The answer depends only on the two addresses and the two lengths.
In the examples, buf is a char buf[16] and every slice is cut out of it.

More examples

ranges_overlap(buf, 4, buf + 4, 4)

Expected result

ranges_overlap(buf, 0, buf, 8)

Expected result

Constraints

Expected files

ranges_overlap.c

Allowed functions

None. Write every helper yourself.

Allowed headers

<stddef.h>defines size_t

Tests

Run the tests to grade your code

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

Build

01Slices far apartWaiting

02First slice ends where the second startsWaiting

03Second slice ends where the first startsWaiting

04Tail of the first slice covers the head of the secondWaiting

05Head of the first slice covers the tail of the secondWaiting

06Same address and same lengthWaiting

07Second slice sits inside the firstWaiting

08First slice sits inside the secondWaiting

09Exactly one shared byte, first slice aheadWaiting

10Exactly one shared byte, second slice aheadWaiting

11Same start, one byte against nineWaiting

12Whole array against its last byteWaiting

13Last byte against everything before itWaiting

14na is zeroWaiting

15nb is zeroWaiting

16Both lengths are zeroWaiting

17Empty slice placed inside a real oneWaiting