栈(stack)是一种比较基础的数据结构,其限制了删除和插入在一个位置操作,而其主要思想就是后进先出(LIFO)。
操作图示:

具体细节可通过代码看出。
下面给出函数的声明部分:
StackRecord.h
#ifndef STACKRECORD_H
#define STACKRECORD_H
typedef char ElementType;
struct StackRecord;
typedef struct StackRecord *Stack;
int IsEmpty(Stack S);
int IsFull(Stack S);
Stack CreateStack(int MaxStackSize);
void DisposeStack(Stack S);
void MakeEmpty(Stack S);
void Push(Stack S, ElementType X);
void Pop(Stack S);
ElementType Top(Stack S);
ElementType PopAndTop(Stack S);
#endif
一般的,当我们创建一个栈时都会声明一个数组来储存元素,但是这是一个隐含的危险,一般数组大小都会有一个确定的值,而通常我们的程序往往潜在的存在多个栈。因此我们动态的申请一个数组,虽然贵这样花费了昂贵的malloc和free程序时间,但是这很符合我们ADT的想法!
栈的主要例程是Push()和Pop()两个例程:
StackFunction.c:
#include"StackRecord.h"
#include<stdio.h>
#include<stdlib.h>
#define EmptyStack -1/*默认空栈大小*/
#define MinStackSize 5
struct StackRecord{
int Capacity;
int TopOfStack;
ElementType *Array;
};
int IsEmpty(Stack S)
{
return S->TopOfStack == EmptyStack;
}
int IsFull(Stack S)
{
return S->Capacity == S->TopOfStack + 1;/*加1因为数组的大小从0开始*/
}
Stack CreateStack(int MaxStackSize)
{
Stack S;
if(MaxStackSize < MinStackSize)
printf("Stack is too small!");
S = (Stack)malloc(sizeof(struct StackRecord));
if(S == NULL)
printf("malloc failure!");
else{ /*Alloc a Arry size you wanted*/
S->Array = (ElementType*)malloc(sizeof(ElementType) * MaxStackSize);
if(S->Array == NULL)
printf("malloc failure!");
else{
S->Capacity = MaxStackSize;
MakeEmpty(S);
}
}
return S;
}
void MakeEmpty(Stack S)
{
S->TopOfStack = EmptyStack;
}
void DisposeStack(Stack S)
{
if(S != NULL){//if S is NULL, that free(S) is meaningless
free(S->Array);
free(S);
}
}
void Push(Stack S, ElementType X)
{
if(IsFull(S))
printf("Stack is full!");
else
S->Array[++S->TopOfStack] = X;
}
void Pop(Stack S)
{
if(IsEmpty(S))
printf("Stack is empty!");
else
S->TopOfStack--;
}
ElementType Top(Stack S)
{
if(!IsEmpty(S))
return S->Array[S->TopOfStack];
printf("Stack is empty!");
return 0;//return value used to avoid warning
}
ElementType PopAndTop(Stack S)
{
if(!IsEmpty(S))
return S->Array[S->TopOfStack--];
printf("Stack is empty!");
return 0;
}