push_swap

Push Swap project | 42 School

The Project

push_swap is a simple and very effective algorithmic project: you have to sort data.

You have at your disposal a set of int values, two stacks and a set of instructions to manipulate both.

What is the objective? Simple: You will write a C program that you will call push_swap.

The program will calculate and display on standard output a list of written instructions. in push_swap language. You must look for the minimum number of instructions to order the set of integers received as an argument.the set of integers received as an argument.

Mandatory part

The rules of the game

• The game is made up of two stacks, called a and b. • For a start:

◦ In a you will have positive and/or negative numbers, never duplicates. ◦ In b there will be nothing. • The goal is to sort the numbers in stack a in ascending order. • To do so you have the following operations at your disposal:

sa : swap a - swaps the first two elements on top of stack a. Does not make nothing if there are one or fewer elements.

sb : swap b - swaps the first two elements on top of stack b. Does not make nothing if there are one or fewer elements.

ss : swap a and swap b at the same time.

pa : push a - takes the first item from stack b and puts it on top of stack a. Does nothing if b is empty.

pb : push b - takes the first element of stack a and puts it on top of stack b. Does nothing if a is empty.

ra : rotate a - shifts all stack items up by one position, so that the first element becomes the last.

rb : rotate b - shifts all elements of stack b up one position, so that the first element becomes the last.

rr : rotate a and rotate b - scroll all the elements of the stack at the same time a and from stack b one position up, so that the first element is becomes the last.

rra : reverse rotate a - scrolls down all items in the stack by a position, so that the last element becomes the first.

rrb : reverse rotate b - scroll down all elements of stack b one position, so that the last element becomes the first.

rrr : reverse rotate a and reverse rotate b- scrolls at the same time all the elements of stack a and stack b one position down, so that the last element becomes the first.

The program: “push_swap"

You must write a program called push_swap that will receive as an argument the stack a in the format of a list of integers. The first argument must be the one be on top of the stack (be careful with the order).

• The program must show the list of instructions (shortest possible) to order the stack a, from lowest to highest where the lowest is at the top of the stack.

• Instructions must be separated using a “\n” and nothing else.

• The objective is to order the stack with the minimum number of operations possible. During the evaluation we will compare the number of instructions obtained by your program with a maximum instruction range.

• Your program will not receive points as much if your program lists too much long as if the result is not correct.

• If no parameters are specified, the program should not display anything and should return control to the user.

• In case of error, you should show Error followed by a “\n” on the standard error output. Some of the possible errors are: arguments that are not integers, arguments greater than an int, and/or find duplicate numbers.

Do you want to check it ? Download

make

If you run the program under Mac

make mtest2
make mtest3
make mtest5
make mtest100
make mtest500
make mtest1000

You can sort 2, 3, 5, 100, 500 or 1000 integers with the commands provided.

Example

jose-aga@c3r5s2 push_swap % make mtest100 ./push_swap -41 -5 49 6 8 -35 10 24 -49 -8 -11 -36 -2 20 22 -21 -17 -4 46 -44 -22 -50 -40 17 -47 -1 -46 0 21 -7 -33 12 -39 -42 23 18 4 44 34 -9 9 -15 -25 -48 30 31 5 26 47 -6 27 40 13 -24 -18 28 -19 -38 -16 35 -34 29 32 -12 -28 -30 -20 14 -3 -37 -14 41 -43 7 37 -31 2 45 -45 42 -32 -29 43 -27 -10 11 25 38 -26 1 48 36 -13 33 -23 39 15 3 19 16 | ./checker_Mac -41 -5 49 6 8 -35 10 24 -49 -8 -11 -36 -2 20 22 -21 -17 -4 46 -44 -22 -50 -40 17 -47 -1 -46 0 21 -7 -33 12 -39 -42 23 18 4 44 34 -9 9 -15 -25 -48 30 31 5 26 47 -6 27 40 13 -24 -18 28 -19 -38 -16 35 -34 29 32 -12 -28 -30 -20 14 -3 -37 -14 41 -43 7 37 -31 2 45 -45 42 -32 -29 43 -27 -10 11 25 38 -26 1 48 36 -13 33 -23 39 15 3 19 16 OK -n Instructions: 592 jose-aga@c3r5s2 push_swap %

OK Indicates that the process is carried out correctly and the number of Instructions is the necessary number of movements to sort the supplied list.

If you run the program under Linux

First of all you have to write in the terminal

make

Then try the test

make test2
make test3
make test5
make test100
make test500
make test1000

jose-aga / push_swap