fizzbuzz/stack/stack.reference.eric.c

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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
* *
* Name: Eric Jacobs *
* What: Stack Implementation *
* Date: Aug 16, 2011 *
* File: stack.c *
* Version:0.1 *
* *
\* * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#include <stdio.h>
#include <stdlib.h>
#include "include/stack.h"
// the implementation of the stack
struct Stack {
struct Node* top;
int length;
};
// Node for the linked list which will make the Stack.
struct Node {
struct Node* prev;
void* v;
};
// Initialize a Node.
struct Node* node_create(struct Node* prev, void* content);
struct Node* node_create(struct Node* prev, void* v) {
struct Node* n = (struct Node*)malloc(sizeof(struct Node));
n->prev = prev;
n->v = v;
return n;
}
struct Stack* s_create() {
struct Stack* s = (struct Stack*)malloc(sizeof(struct Stack));
s->top = NULL;
s->length = 0;
return s;
}
int s_length(struct Stack* s) {
return s->length;
}
int s_push(struct Stack* s, void* v) {
struct Node* new_node = node_create(s->top, v);
s->top = new_node;
return ++s->length;
}
void* s_pop(struct Stack* s) {
if(s->top == NULL) {
return NULL;
}
struct Node* node_tbd = s->top;
void* v = node_tbd->v;
s->top = node_tbd->prev;
free(node_tbd);
node_tbd = NULL;
s->length--;
return v;
}
void* s_peek(struct Stack* s) {
if(s->top == NULL) {
return NULL;
}
return s->top->v;
}
void s_destroy(struct Stack* s) {
while(s->length > 0) {
s_pop(s);
}
free(s);
s = NULL;
}