v0.40: Create exercises. Challenge the community.

chess_check

Your mission

Given a square chess board passed as a single argument, decide whether the King is currently under attack by any other piece.

See it in action

./chess_check $'B....\n.....\n..K..\n.....\n.....'

Expected result

Success

Your checklist

For your own tracking. Tests grade your code.

The program must receive exactly one argument (argc must be 2): a square board whose rows are separated by newline characters.
Each cell is one of: K for the King (exactly one), P for a Pawn, R for a Rook, B for a Bishop, Q for a Queen, or . for an empty square.
A Pawn threatens the two squares diagonally above it (north-west and north-east).
A Rook threatens straight rank and file lines, stopping at the first non-empty square along each direction.
A Bishop threatens diagonal lines, stopping at the first non-empty square along each direction.
A Queen threatens both straight and diagonal lines, again stopping at the first non-empty square.
Print Success followed by a newline if at least one piece attacks the King. Otherwise print Fail followed by a newline.
If the program does not receive exactly one argument, or if the board does not contain a King, the program must print nothing.

More examples

./chess_check $'.....\n.....\n..K..\n.....\n.....'

Expected result

Fail

Constraints

Expected files

chess_check.c

Allowed functions

write

chess_check

Arrays and matrices

Your mission

Given a square chess board passed as a single argument, decide whether the King is currently under attack by any other piece.

See it in action

./chess_check $'B....\n.....\n..K..\n.....\n.....'

Expected result

Success

Your checklist

For your own tracking. Tests grade your code.

The program must receive exactly one argument (argc must be 2): a square board whose rows are separated by newline characters.
Each cell is one of: K for the King (exactly one), P for a Pawn, R for a Rook, B for a Bishop, Q for a Queen, or . for an empty square.
A Pawn threatens the two squares diagonally above it (north-west and north-east).
A Rook threatens straight rank and file lines, stopping at the first non-empty square along each direction.
A Bishop threatens diagonal lines, stopping at the first non-empty square along each direction.
A Queen threatens both straight and diagonal lines, again stopping at the first non-empty square.
Print Success followed by a newline if at least one piece attacks the King. Otherwise print Fail followed by a newline.
If the program does not receive exactly one argument, or if the board does not contain a King, the program must print nothing.

More examples

./chess_check $'.....\n.....\n..K..\n.....\n.....'

Expected result

Fail

Constraints

Expected files

chess_check.c

Allowed functions

write

Tests

Run the tests to grade your code

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

Build

01Missing board argument prints nothingWaiting

02Bishop attacks King along an open diagonalWaiting

03Rook attacks King down an open fileWaiting

04Queen attacks King along an open rankWaiting

05Pawn threatens King from the south-east diagonal squareWaiting

06Pawn blocks the Rook before it reaches the KingWaiting

07Pawn on the diagonal blocks the BishopWaiting

08King alone on an empty board is safeWaiting

09Board without a King produces no outputWaiting

chess_check

Your mission

Given a square chess board passed as a single argument, decide whether the King is currently under attack by any other piece.

See it in action

./chess_check $'B....\n.....\n..K..\n.....\n.....'

Expected result

Success

Your checklist

For your own tracking. Tests grade your code.

The program must receive exactly one argument (argc must be 2): a square board whose rows are separated by newline characters.
Each cell is one of: K for the King (exactly one), P for a Pawn, R for a Rook, B for a Bishop, Q for a Queen, or . for an empty square.
A Pawn threatens the two squares diagonally above it (north-west and north-east).
A Rook threatens straight rank and file lines, stopping at the first non-empty square along each direction.
A Bishop threatens diagonal lines, stopping at the first non-empty square along each direction.
A Queen threatens both straight and diagonal lines, again stopping at the first non-empty square.
Print Success followed by a newline if at least one piece attacks the King. Otherwise print Fail followed by a newline.
If the program does not receive exactly one argument, or if the board does not contain a King, the program must print nothing.

More examples

./chess_check $'.....\n.....\n..K..\n.....\n.....'

Expected result

Fail

Constraints

Expected files

chess_check.c

Allowed functions

write

v0.40: Create exercises. Challenge the community.

Meet Studio →

chess_check

Arrays and matrices

Your mission

Given a square chess board passed as a single argument, decide whether the King is currently under attack by any other piece.

See it in action

./chess_check $'B....\n.....\n..K..\n.....\n.....'

Expected result

Success

Your checklist

For your own tracking. Tests grade your code.

The program must receive exactly one argument (argc must be 2): a square board whose rows are separated by newline characters.
Each cell is one of: K for the King (exactly one), P for a Pawn, R for a Rook, B for a Bishop, Q for a Queen, or . for an empty square.
A Pawn threatens the two squares diagonally above it (north-west and north-east).
A Rook threatens straight rank and file lines, stopping at the first non-empty square along each direction.
A Bishop threatens diagonal lines, stopping at the first non-empty square along each direction.
A Queen threatens both straight and diagonal lines, again stopping at the first non-empty square.
Print Success followed by a newline if at least one piece attacks the King. Otherwise print Fail followed by a newline.
If the program does not receive exactly one argument, or if the board does not contain a King, the program must print nothing.

More examples

./chess_check $'.....\n.....\n..K..\n.....\n.....'

Expected result

Fail

Constraints

Expected files

chess_check.c

Allowed functions

write

Tests

Run the tests to grade your code

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

Build

01Missing board argument prints nothingWaiting

02Bishop attacks King along an open diagonalWaiting

03Rook attacks King down an open fileWaiting

04Queen attacks King along an open rankWaiting

05Pawn threatens King from the south-east diagonal squareWaiting

06Pawn blocks the Rook before it reaches the KingWaiting

07Pawn on the diagonal blocks the BishopWaiting

08King alone on an empty board is safeWaiting

09Board without a King produces no outputWaiting