hanoi-moves

Recursion16

Objective

Write a program that prints the moves solving the Tower of Hanoi for the disk count given as its single argument, one move per line.

Steps

Read the disk count from argv[1] and parse it with atoi.
The towers are named A, B and C. Every disk starts on A, all of them must end on C, and B is the spare tower.
A move is one line: the source tower, a single space, the destination tower, then a newline. Taking the top disk of A and dropping it on C prints A C.
Recurse in the canonical order, which makes the sequence unique. To move count disks from X to Z through Y: move count - 1 disks from X to Y, print the move X Z, then move count - 1 disks from Y to Z.
A count of n takes 2^n - 1 moves, so 3 disks print 7 lines and 6 disks print 63. What is graded is the lines, in order, not their total.
A count of zero prints nothing at all.
A negative count prints nothing either, and an argument that is not a number reads as zero, so it prints nothing too.
If the program does not receive exactly one argument, print wrong number of arguments followed by a newline.

examples

$ ./hanoi_moves 1 | cat -e

A C$

$ ./hanoi_moves 2 | cat -e

A B$ A C$ B C$

$ ./hanoi_moves 3 | cat -e

A C$ A B$ C B$ A C$ B A$ B C$ A C$

$ ./hanoi_moves 0 | cat -e

(no output)

$ ./hanoi_moves 3 2 | cat -e

wrong number of arguments$

Constraints

Expected files

hanoi_moves.c

Allowed functions

atoiwrite

Tests

Run the tests to grade your code

Build

01No arguments

02Two arguments

03Zero disks prints nothing

04One disk is a single move

05Two disks

06Three disks

07Four disks

08Five disks

09Six disks is sixty-three moves

10Negative count prints nothing

11Non-numeric count prints nothing

12Empty argument prints nothing

hanoi-moves

Objective

Write a program that prints the moves solving the Tower of Hanoi for the disk count given as its single argument, one move per line.

Steps

Read the disk count from argv[1] and parse it with atoi.
The towers are named A, B and C. Every disk starts on A, all of them must end on C, and B is the spare tower.
A move is one line: the source tower, a single space, the destination tower, then a newline. Taking the top disk of A and dropping it on C prints A C.
Recurse in the canonical order, which makes the sequence unique. To move count disks from X to Z through Y: move count - 1 disks from X to Y, print the move X Z, then move count - 1 disks from Y to Z.
A count of n takes 2^n - 1 moves, so 3 disks print 7 lines and 6 disks print 63. What is graded is the lines, in order, not their total.
A count of zero prints nothing at all.
A negative count prints nothing either, and an argument that is not a number reads as zero, so it prints nothing too.
If the program does not receive exactly one argument, print wrong number of arguments followed by a newline.

examples

$ ./hanoi_moves 1 | cat -e

A C$

$ ./hanoi_moves 2 | cat -e

A B$ A C$ B C$

$ ./hanoi_moves 3 | cat -e

A C$ A B$ C B$ A C$ B A$ B C$ A C$

$ ./hanoi_moves 0 | cat -e

(no output)

$ ./hanoi_moves 3 2 | cat -e

wrong number of arguments$

Constraints

Expected files

hanoi_moves.c

Allowed functions

atoiwrite

hanoi-moves

Recursion16

Objective

Write a program that prints the moves solving the Tower of Hanoi for the disk count given as its single argument, one move per line.

Steps

Read the disk count from argv[1] and parse it with atoi.
The towers are named A, B and C. Every disk starts on A, all of them must end on C, and B is the spare tower.
A move is one line: the source tower, a single space, the destination tower, then a newline. Taking the top disk of A and dropping it on C prints A C.
Recurse in the canonical order, which makes the sequence unique. To move count disks from X to Z through Y: move count - 1 disks from X to Y, print the move X Z, then move count - 1 disks from Y to Z.
A count of n takes 2^n - 1 moves, so 3 disks print 7 lines and 6 disks print 63. What is graded is the lines, in order, not their total.
A count of zero prints nothing at all.
A negative count prints nothing either, and an argument that is not a number reads as zero, so it prints nothing too.
If the program does not receive exactly one argument, print wrong number of arguments followed by a newline.

examples

$ ./hanoi_moves 1 | cat -e

A C$

$ ./hanoi_moves 2 | cat -e

A B$ A C$ B C$

$ ./hanoi_moves 3 | cat -e

A C$ A B$ C B$ A C$ B A$ B C$ A C$

$ ./hanoi_moves 0 | cat -e

(no output)

$ ./hanoi_moves 3 2 | cat -e

wrong number of arguments$

Constraints

Expected files

hanoi_moves.c

Allowed functions

atoiwrite

Tests

Run the tests to grade your code

Build

01No arguments

02Two arguments

03Zero disks prints nothing

04One disk is a single move

05Two disks

06Three disks

07Four disks

08Five disks

09Six disks is sixty-three moves

10Negative count prints nothing

11Non-numeric count prints nothing

12Empty argument prints nothing