v0.40: Create exercises. Challenge the community.

is_sorted

Your mission

Write a function that reports whether the first n values of a are in ascending order, where two equal neighbours still count as ordered.

See it in action

const int a[] = {1, 2, 2, 5}; is_sorted(a, 4);

Expected result

Your checklist

For your own tracking. Tests grade your code.

a points to n integers. Read exactly n of them, never a[n], and never write through the pointer.
Return 1 when the values never decrease as you walk forward. Return 0 at the first value smaller than the one before it.
Ascending here is the loose kind: a[i] == a[i - 1] is allowed and keeps the answer 1. Only a strict drop breaks the order.
n of 0 returns 1, and n of 1 returns 1. Nothing to compare means nothing out of order, so an empty or single element buffer counts as sorted by convention.
Compare the two values against each other. Subtracting them overflows when INT_MIN sits next to INT_MAX.
The examples print what the call returns.

More examples

const int a[] = {4, 1, 9}; is_sorted(a, 3);

Expected result

const int a[] = {7}; is_sorted(a, 0);

Expected result

const int a[] = {INT_MIN, INT_MAX}; is_sorted(a, 2);

Expected result

Constraints

Expected files

is_sorted.c

Allowed functions

None. Write every helper yourself.

Allowed headers

<stddef.h>defines size_t

is_sorted

Sorting and searching

Your mission

Write a function that reports whether the first n values of a are in ascending order, where two equal neighbours still count as ordered.

See it in action

const int a[] = {1, 2, 2, 5}; is_sorted(a, 4);

Expected result

Your checklist

For your own tracking. Tests grade your code.

a points to n integers. Read exactly n of them, never a[n], and never write through the pointer.
Return 1 when the values never decrease as you walk forward. Return 0 at the first value smaller than the one before it.
Ascending here is the loose kind: a[i] == a[i - 1] is allowed and keeps the answer 1. Only a strict drop breaks the order.
n of 0 returns 1, and n of 1 returns 1. Nothing to compare means nothing out of order, so an empty or single element buffer counts as sorted by convention.
Compare the two values against each other. Subtracting them overflows when INT_MIN sits next to INT_MAX.
The examples print what the call returns.

More examples

const int a[] = {4, 1, 9}; is_sorted(a, 3);

Expected result

const int a[] = {7}; is_sorted(a, 0);

Expected result

const int a[] = {INT_MIN, INT_MAX}; is_sorted(a, 2);

Expected result

Constraints

Expected files

is_sorted.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

01n of zero is sortedWaiting

02A single value is sortedWaiting

03Strictly ascending runWaiting

04Pair in ascending orderWaiting

05Pair in descending orderWaiting

06Pair of equal valuesWaiting

07Inversion on the last pairWaiting

08Inversion on the first pairWaiting

09Inversion in the middleWaiting

10Exactly reverse orderWaiting

11All values identicalWaiting

12Runs of equal neighbours stay sortedWaiting

13One dip between two equal runsWaiting

14Negatives in ascending orderWaiting

15Negatives out of orderWaiting

16INT_MIN and INT_MAX at the endsWaiting

17Widest possible gap, still sortedWaiting

18Widest possible gap, reversedWaiting

19Reads exactly n valuesWaiting

20Sorted prefix, unsorted wholeWaiting

is_sorted

Your mission

Write a function that reports whether the first n values of a are in ascending order, where two equal neighbours still count as ordered.

See it in action

const int a[] = {1, 2, 2, 5}; is_sorted(a, 4);

Expected result

Your checklist

For your own tracking. Tests grade your code.

a points to n integers. Read exactly n of them, never a[n], and never write through the pointer.
Return 1 when the values never decrease as you walk forward. Return 0 at the first value smaller than the one before it.
Ascending here is the loose kind: a[i] == a[i - 1] is allowed and keeps the answer 1. Only a strict drop breaks the order.
n of 0 returns 1, and n of 1 returns 1. Nothing to compare means nothing out of order, so an empty or single element buffer counts as sorted by convention.
Compare the two values against each other. Subtracting them overflows when INT_MIN sits next to INT_MAX.
The examples print what the call returns.

More examples

const int a[] = {4, 1, 9}; is_sorted(a, 3);

Expected result

const int a[] = {7}; is_sorted(a, 0);

Expected result

const int a[] = {INT_MIN, INT_MAX}; is_sorted(a, 2);

Expected result

Constraints

Expected files

is_sorted.c

Allowed functions

None. Write every helper yourself.

Allowed headers

<stddef.h>defines size_t

v0.40: Create exercises. Challenge the community.

Meet Studio →

is_sorted

Sorting and searching

Your mission

Write a function that reports whether the first n values of a are in ascending order, where two equal neighbours still count as ordered.

See it in action

const int a[] = {1, 2, 2, 5}; is_sorted(a, 4);

Expected result

Your checklist

For your own tracking. Tests grade your code.

a points to n integers. Read exactly n of them, never a[n], and never write through the pointer.
Return 1 when the values never decrease as you walk forward. Return 0 at the first value smaller than the one before it.
Ascending here is the loose kind: a[i] == a[i - 1] is allowed and keeps the answer 1. Only a strict drop breaks the order.
n of 0 returns 1, and n of 1 returns 1. Nothing to compare means nothing out of order, so an empty or single element buffer counts as sorted by convention.
Compare the two values against each other. Subtracting them overflows when INT_MIN sits next to INT_MAX.
The examples print what the call returns.

More examples

const int a[] = {4, 1, 9}; is_sorted(a, 3);

Expected result

const int a[] = {7}; is_sorted(a, 0);

Expected result

const int a[] = {INT_MIN, INT_MAX}; is_sorted(a, 2);

Expected result

Constraints

Expected files

is_sorted.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

01n of zero is sortedWaiting

02A single value is sortedWaiting

03Strictly ascending runWaiting

04Pair in ascending orderWaiting

05Pair in descending orderWaiting

06Pair of equal valuesWaiting

07Inversion on the last pairWaiting

08Inversion on the first pairWaiting

09Inversion in the middleWaiting

10Exactly reverse orderWaiting

11All values identicalWaiting

12Runs of equal neighbours stay sortedWaiting

13One dip between two equal runsWaiting

14Negatives in ascending orderWaiting

15Negatives out of orderWaiting

16INT_MIN and INT_MAX at the endsWaiting

17Widest possible gap, still sortedWaiting

18Widest possible gap, reversedWaiting

19Reads exactly n valuesWaiting

20Sorted prefix, unsorted wholeWaiting