v0.40: Create exercises. Challenge the community.

header_guard

Your mission

Make counter.h safe to include more than once, then implement the three functions it declares.

See it in action

counter c = { 7 }; counter_add(&c, 5); counter_value(&c)

Expected result

Your checklist

For your own tracking. Tests grade your code.

Write counter.h and counter.c.
Keep the counter type and the three function signatures from the starter.
Protect the whole header with an include guard. Grademe includes it twice in the same source file.
counter_reset stores zero in the counter.
counter_add adds amount to the current value. Negative amounts are valid.
counter_value returns the current value without modifying the counter.
Do not use global or static storage. Two counter values must remain independent.

More examples

counter c = { 7 }; counter_reset(&c); counter_value(&c)

Expected result

Constraints

Expected files

counter.hcounter.c

Allowed functions

None. Write every helper yourself.

header_guard

Headers and the preprocessor

Your mission

Make counter.h safe to include more than once, then implement the three functions it declares.

See it in action

counter c = { 7 }; counter_add(&c, 5); counter_value(&c)

Expected result

Your checklist

For your own tracking. Tests grade your code.

Write counter.h and counter.c.
Keep the counter type and the three function signatures from the starter.
Protect the whole header with an include guard. Grademe includes it twice in the same source file.
counter_reset stores zero in the counter.
counter_add adds amount to the current value. Negative amounts are valid.
counter_value returns the current value without modifying the counter.
Do not use global or static storage. Two counter values must remain independent.

More examples

counter c = { 7 }; counter_reset(&c); counter_value(&c)

Expected result

Constraints

Expected files

counter.hcounter.c

Allowed functions

None. Write every helper yourself.

Tests

Run the tests to grade your code

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

Build

01Reset stores zeroWaiting

02Adds a positive amountWaiting

03Adds a negative amountWaiting

04Counters do not share storageWaiting

header_guard

Your mission

Make counter.h safe to include more than once, then implement the three functions it declares.

See it in action

counter c = { 7 }; counter_add(&c, 5); counter_value(&c)

Expected result

Your checklist

For your own tracking. Tests grade your code.

Write counter.h and counter.c.
Keep the counter type and the three function signatures from the starter.
Protect the whole header with an include guard. Grademe includes it twice in the same source file.
counter_reset stores zero in the counter.
counter_add adds amount to the current value. Negative amounts are valid.
counter_value returns the current value without modifying the counter.
Do not use global or static storage. Two counter values must remain independent.

More examples

counter c = { 7 }; counter_reset(&c); counter_value(&c)

Expected result

Constraints

Expected files

counter.hcounter.c

Allowed functions

None. Write every helper yourself.

header_guard

Headers and the preprocessor

Your mission

Make counter.h safe to include more than once, then implement the three functions it declares.

See it in action

counter c = { 7 }; counter_add(&c, 5); counter_value(&c)

Expected result

Your checklist

For your own tracking. Tests grade your code.

Write counter.h and counter.c.
Keep the counter type and the three function signatures from the starter.
Protect the whole header with an include guard. Grademe includes it twice in the same source file.
counter_reset stores zero in the counter.
counter_add adds amount to the current value. Negative amounts are valid.
counter_value returns the current value without modifying the counter.
Do not use global or static storage. Two counter values must remain independent.

More examples

counter c = { 7 }; counter_reset(&c); counter_value(&c)

Expected result

Constraints

Expected files

counter.hcounter.c

Allowed functions

None. Write every helper yourself.

Tests

Run the tests to grade your code

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

Build

01Reset stores zeroWaiting

02Adds a positive amountWaiting

03Adds a negative amountWaiting

04Counters do not share storageWaiting

v0.40: Create exercises. Challenge the community.

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