一、栈的定义
栈是限定仅在表尾进行插入或删除操作的线性表。
栈的表尾称为栈顶，表头称为栈底，不含元素的空表称为空栈。
栈的抽象数据类型定义：
ADT Stack{
数据对象:D={ai|ai(- ElemSet,i=1,2,...,n,n>=0}
数据关系:R1={<ai-1,ai>|ai-1,ai(- D,i=2,...,n}
基本操作:
InitStack(&S) 构造一个空栈S
DestroyStack(&S) 栈S存在则栈S被销毁
ClearStack(&S) 栈S存在则清为空栈
StackEmpty(S) 栈S存在则返回TRUE,否则FALSE
StackLength(S) 栈S存在则返回S的元素个数,即栈的长度
GetTop(S,&e) 栈S存在且非空则返回S的栈顶元素
Push(&S,e) 栈S存在则插入元素e为新的栈顶元素
Pop(&S,&e) 栈S存在且非空则删除S的栈顶元素并用e返回其值
StackTraverse(S,visit())栈S存在且非空则从栈底到栈顶依次对S的每个数据元素调用函数visit()一旦visit()失败,则操作失败
}ADT Stack
二、栈的表示和实现
栈的存储方式：
1、顺序栈:利用一组地址连续的存储单元依次存放自栈底到栈顶的数据元素,同时附设指针top指示栈顶元素在顺序栈中的位置
2、链栈:利用链表实现
顺序栈的类C语言定义:
typedef struct{
SElemType *base;
SElemType *top; //设栈顶栈底两指针的目的是便于判断栈是否为空
int StackSize; //栈的当前可使用的最大容量.
}SqStack;
顺序栈的的模块说明:
struct STACK {
SElemType *base;
SElemType *top;
int stacksize;
};
typedef struct STACK Sqstack;
Status InitStack(SqStack &S);
Status DestroyStack(SqStack &S);
Status ClearStack(SqStack &S);
Status StackEmpty(SqStack S);
int StackLength(SqStack S);
Status GetTop(SqStack S,SElemType &e);
Status Push(SqStack &S,SElemType e);
Status Pop(SqStack &S,SElemType &e);
Status StackTraverse(SqStack S,Status (*visit)());
Status InitStack(SqStack &S) {
S.base=(SelemType *)malloc(STACK_INIT_SIZE *sizeof(ElemType));
if(!S.base)exit(OVERFLOW);
S.top=S.base;
S.stacksize=STACK_INI_SIZE;
return OK;
}//IniStack
Status DestroyStack(SqStack &S); {
}//DestroyStack
Status ClearStack(SqStack &S); {
S.top=S.base;
} //ClearStack
Status StackEmpty(SqStack S); {
if(S.top==S.base) return TRUE;
else return FALSE;
} //StackEmpty
int StackLength(SqStack S); {
int i; SElemType *p;
i=0;
p=S.top;
while(p!=S.base) {p++; i++; }
} //stackLength
Status GetTop(SqStack S,SElemType &e); {
if(S.top==S.base) return ERROR;
e=*(S.top-1);
return OK;
} //GetTop
Status Push(SqStack &S,SElemType e); {
if(S.top - s.base>=S.stacksize) {
S.base=(ElemType *) realloc(S.base,
(S.stacksize + STACKINCREMENT) * sizeof(ElemType));
if(!S.base)exit(OVERFLOW);
S.top=S.base+S.stacksize;
S.stacksize+=STACKINCREMENT;
}
*S.top++=e;
return OK;
} //Push
Status Pop(SqStack &S,SElemType &e); {
if(S.top==S.base)
return ERROR;
e=*--S.top;
return OK;
}//Pop
Status StackTraverse(SqStack S,Status (*visit)()); {
}//StackTraverse
源码
#include<stdio.h>
#include<malloc.h>
#define ERROR 0
#define TRUE 1
#define FALSE 0
#define OK 1
#define EQUAL 1
#define OVERFLOW -1
#define STACK_INIT_SIZE 100
#define STACKINCREMENT 10
typedef int Status ;
struct STU{
char name[20];
char stuno[10];
int age;
int score;
};
typedef struct STU SElemType;
struct STACK
{
SElemType *base;
SElemType *top;
int stacksize;
};
typedef struct STACK SqStack;
typedef struct STACK *pSqstack;
Status InitStack(SqStack **S); /*构造空栈S*/
Status DestroyStack(SqStack *S); /*销毁栈S*/
Status ClearStack(SqStack *S); /*把S置为空栈*/
Status StackEmpty(SqStack S); /*若栈为空栈,则返回TRUE,否则返回FALSE*/
int StackLength(SqStack S); /*返回S的元素个数*/
Status GetTop(SqStack S,SElemType *e); /*若栈不空,则用e返回S的栈顶元素,并返回OK;否则返回ERROR*/
Status Push(SqStack *S,SElemType e); /*插入元素e为新的栈顶元素*/
Status Pop(SqStack *S,SElemType *e); /*若栈不空,则删除S的栈顶元素,用e返回其值,并返回OK,否则返回ERRO*/
Status StackTraverse(SqStack S,Status (*visit)()); /*从栈底到栈顶依次对每个元素调用visit(),一旦visit()失败,则操作失败*/
Status InitStack(SqStack **S)
{
(*S)=(SqStack *)malloc(sizeof(SqStack));
(*S)->base=(SElemType *)malloc(STACK_INIT_SIZE *sizeof(SElemType));
if(!(*S)->base)exit(OVERFLOW);
(*S)->top=(*S)->base;
(*S)->stacksize=STACK_INIT_SIZE;
return OK;
}
Status DestroyStack(SqStack *S)
{
free(S->base);
free(S);
}
Status ClearStack(SqStack *S)
{
S->top=S->base;
}
Status StackEmpty(SqStack S)
{
if(S.top==S.base) return TRUE;
else
return FALSE;
}
int StackLength(SqStack S)
{
int i;
SElemType *p;
i=0;
p=S.top;
while(p!=S.base)
{p++;
i++;
}
}
Status GetTop(SqStack S,SElemType *e)
{
if(S.top==S.base) return ERROR;
*e=*(S.top-1);
return OK;
}
Status Push(SqStack *S,SElemType e)
{
/*
if(S->top - S->base>=S->stacksize)
{
S->base=(SElemType *) realloc(S->base,
(S->stacksize + STACKINCREMENT) * sizeof(SElemType));
if(!S->base)exit(OVERFLOW);
S->top=S->base+S->stacksize;
S->stacksize += STACKINCREMENT;
}
*/
*(S->top++)=e;
return OK;
}
Status Pop(SqStack *S,SElemType *e)
{
if(S->top==S->base) return ERROR;
*e=*--S->top;
return OK;
}
Status StackPrintElem(SElemType * e)
{
printf("%s %s %d %d\n",e->name,e->stuno,e->age,e->score);
}
Status StackTraverse(SqStack S,Status (*visit)())
{
while(S.top!=S.base)
visit(--S.top);
}
main()
{
SElemType e;
SqStack *Sa;
/*clrscr();*/
printf("\n\n-------------------SqStack Demo is running...----------------\n\n");
printf("First is Push function.\n");
InitStack(&Sa);
strcpy(e.name,"stu1");
strcpy(e.stuno,"100001");
e.age=80;
e.score=1000;
printf(" Now Stack is Empty.\n");
StackTraverse(*Sa,StackPrintElem);
Push(Sa,e);
printf(" Now Stack has one element.\n");
StackTraverse(*Sa,StackPrintElem);
strcpy(e.name,"stu3");
strcpy(e.stuno,"100002");
e.age=80;
e.score=1000;
Push(Sa,e);
printf(" Now Stack has another element.\n");
StackTraverse(*Sa,StackPrintElem);
printf(" Now Pop Stack,the top elem put into variable e.\n");
Pop(Sa,&e);
printf("%s\n%s\n%d\n%d\n",e.name,e.stuno,e.age,e.score);
printf(" Let's see the left of Stack's elem:\n");
StackTraverse(*Sa,StackPrintElem);
getch();
printf("\n\n\nWelcom to visit http://zmofun.topcool.net\n\n");
}