/****************************************************************
Title : stack.c
Author : 张龙
Time : 200508
*****************************************************************/
#include "stdio.h"
#define STACK_SIZE 100
typedef int ElementType;
typedef struct _stacknode
{
ElementType data;
struct _stacknode *next;
} stacknode;
typedef struct _stack
{
stacknode *top,*bottom;
int count;
} stack;
/*========================functions declaration===================*/
void init(stack *s);
int IsEmpty(stack *s);
int IsFull(stack *s);
int GetStackSize();
int length(stack *s);
ElementType top(stack *s);
int push(stack *s,ElementType x);
int pop(stack *s);
/*====================function implementation================*/
void init(stack *s)
{
s->top=s->bottom=0;
s->count=0;
}
int IsEmpty(stack *s)
{
if(!s->count)
return 1;
else
return 0;
}
int IsFull(stack *s)
{
if(s->count==STACK_SIZE)
return 1;
else
return 0;
}
int GetStackSize()
{
return STACK_SIZE;
}
int length(stack *s)
{
return s->count;
}
ElementType top(stack *s)
{
return s->top->data;
}
int push(stack *s,ElementType x)
{
stacknode *node;
if(IsFull(s)){
printf("the stack is full,no new data can be inserted.\n");
return 0;
}
if(!s->bottom){
node=s->bottom=s->top=(stacknode *)malloc(sizeof(stacknode));
node->data=x;
}
else{
node=(stacknode *)malloc(sizeof(stacknode));
node->data=x;
s->top->next=node;
s->top=node;
}
s->count++;
return;
}
ElementType pop(stack *s)
{
int i,j;
ElementType data;
stacknode *node;
if(IsEmpty(s)){
printf("the stack is empty,no data is popped up\n");
return 0;
}
data=s->top->data;
free(s->top);
s->count--;
j=s->count;
if(j==1){
s->top=s->bottom;
s->top->next=0;
}
else{
for(i=0;i<j;i++){
if(i==0){
node=s->bottom;
}
else{
node=node->next;
}
}
s->top=node;
s->top->next=0;
}
return data;
}
/*========================main function========================*/
int main(int argc,char*argv[])
{
int i,j;
stack *mystack;
mystack=(stack *)malloc(sizeof(stack));
init(mystack);
for(i=0;i<100;i++){
j=i+3;
push(mystack,j);
printf("%d ",top(mystack));
}
printf("\n");
printf("the size of stack is %d\n",GetStackSize());
printf("the current length of stack is %d\n",length(mystack));
for(i=0;i<50;i++){
printf("%d ",pop(mystack));
}
printf("\n");
printf("the size of stack is %d\n",GetStackSize());
printf("the current length of stack is %d\n",length(mystack));
return 1;
}
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