堆栈

/*实现堆栈的初始化，入栈，出栈*/
#include<stdio.h>
#include<stdlib.h>
#include<string.h>

#define STACK_INIT_SIZE 100
#define INCREMENT 10

typedef struct stack{
 int * top;
 int * base;
 int stacksize;
}Stack;

int n;

void Init_Stack(Stack * S)/*堆栈初始化*/
{
 S->base=(int *)malloc(STACK_INIT_SIZE * sizeof(int));
 if(!S->base){printf("error!\n");exit(0);}
 S->top=S->base;
 S->stacksize=STACK_INIT_SIZE;
}

void Push_Stack(Stack * S,int e)/*堆栈入栈*/
{
 if((S->top-S->base)>=S->stacksize)
 {
  S->base=(int *)realloc(S->base,(S->stacksize+INCREMENT)*sizeof(int));
  if(!S->base)exit(0);
  S->top=S->base+S->stacksize;
  S->stacksize=S->stacksize+INCREMENT;
 }
 *S->top++=e;
 n++;
}

void Pop_Stack(Stack * S,int * e)/*堆栈出栈*/
{
 if(S->base==S->top)exit(0);
 *e=*--S->top;
 n--;
}

void Print_Stack(struct stack * S)/*显示堆栈数据*/
{
 int i;
 int * p1;
 p1=S->base;
 printf("\nNow stack have %d data:\n",n);
 for(i=0;i<n;i++){
  printf("%d  ",*p1++);
 }
 printf("\n");
}

int main(int argc,char **argv)
{
 struct stack S;
 int k,j;
 Init_Stack(&S);
 Push_Stack(&S,12);
 Push_Stack(&S,34);
 Push_Stack(&S,56);
 Print_Stack(&S);
 Pop_Stack(&S,&k);
 printf("\n%d data pop stack!\n",k);
 Pop_Stack(&S,&j);
 printf("%d data pop stack!\n",j);
 Print_Stack(&S);
 return 0;
}