push_swap

V.1 Game rules • The game is composed of 2 stacks named a and b. • To start with: ◦ a contains a random number of either positive or negative numbers without any duplicates. ◦ b is empty • The goal is to sort in ascending order numbers into stack a. • To do this you have the following operations at your disposal: sa : swap a - swap the first 2 elements at the top of stack a. Do nothing if there is only one or no elements). sb : swap b - swap the first 2 elements at the top of stack b. Do nothing if there is only one or no elements). ss : sa and sb at the same time. pa : push a - take the first element at the top of b and put it at the top of a. Do nothing if b is empty. pb : push b - take the first element at the top of a and put it at the top of b. Do nothing if a is empty. ra : rotate a - shift up all elements of stack a by 1. The first element becomes the last one. rb : rotate b - shift up all elements of stack b by 1. The first element becomes the last one. rr : ra and rb at the same time. rra : reverse rotate a - shift down all elements of stack a by 1. The last element becomes the first one. rrb : reverse rotate b - shift down all elements of stack b by 1. The last element becomes the first one. rrr : rra and rrb at the same time. The “push_swap” program • You have to write a program named push_swap which will receive as an argument the stack a formatted as a list of integers. The first argument should be at the top of the stack (be careful about the order). • The program must display the smallest list of instructions possible to sort the stack a, the smallest number being at the top. • Instructions must be separaed by a ’\n’ and nothing else. • The goal is to sort the stack with the minimum possible number of operations. During defence we’ll compare the number of instructions your program found with a maximum number of operations tolerated. If your program either displays a list too big or if the list isn’t sorted properly, you’ll get no points. • In case of error, you must display Error followed by a ’\n’ on the standard error. Errors include for example: some arguments aren’t integers, some arguments are bigger than an integer, and/or there are duplicates.