Answer in C language

1) [15 points] Stacks:

In this question you may assume that the functions below are implemented.

You cannot make assumptions about how the stack is implemented. If you want to use any other function, you need to implement it.

typedef struct { ... // not known

} stack_t;

// creates a new stack stack_t* stack_create();

// pushes a given item to the stack void stack_push(stack_t* s, int item);

// pops the top element from the stack // Pre condition: stack is not empty int stack_pop(stack_t* s);

// checks if the stack is empty bool stack_is_empty(stack_t* s);

// frees the stack void stack_free(stack_t* s);