stack.c

#include <stdio.h>
#include <stdlib.h>

#define STACK_MAXSIZE 50

struct _Stack
{
    Node *stk[STACK_MAXSIZE];
    int top;
};
typedef struct _Stack Stack;

struct node{
    float freq;
    unsigned char symbol;
    int height;
    int depth;
    unsigned char code[20];
    struct node *left,*right;
};
typedef struct node Node;

void push (Stack *s, Node* node)
{
    if (s->top == (STACK_MAXSIZE - 1))
    {
        printf ("Stack is full\n");
        return;
    }
    else
    {
        s->top = s->top + 1;
        s->stk[s->top] = node;
    }
    return;
}

Node* pop (Stack *s)
{
    Node* node;
    if (s->top == - 1)
    {
        printf ("Stack is Empty\n");
        return NULL;
    }
    else
    {
        node = s->stk[s->top];
        s->top = s->top - 1;
    }
    return node;
}

int empty(Stack *s){
	if (s->top == -1){
		return 1;
	}
	return 0;
}

void init_Stack(Stack* s){
	s->top = -1;
}