数据结构之栈（二）

Stack.c

1.头文件的声明

#include “Stack.h”

2.初始化和销毁函数的定义

/初始化
void STInit(ST* ps)
{
    assert(ps);
    ps->a = NULL;
    ps->capacity = 0;
    ps->top = 0;
}

//销毁
void STDestroy(ST* ps)
{
    assert(ps);
    free(ps->a);
    ps->a = NULL;
    ps->top = ps->capacity = 0;
}

3.入栈和出栈函数的定义

//插入
void STPush(ST* ps, STDataType x)
{
    assert(ps);
    if (ps->top == ps->capacity)
    {
        int newCapacity = ps->capacity == 0 ? 4 : ps->capacity * 2;
        STDataType* tmp = (STDataType*)realloc(ps->a, sizeof(STDataType) * newCapacity);
        if (tmp == NULL)
        {
            perror(“realloc fail”);
            exit(-1);
        }

        ps->a = tmp;
        ps->capacity = newCapacity;
    }

    ps->a[ps->top] = x;
    ps->top++;
}

//删除栈顶元素
void STPop(ST* ps)
{
    assert(ps);
    assert(ps->top > 0);
    –ps->top;
}

4.查找栈顶元素和长度计算函数以及判空函数的定义

//查找栈顶元素
STDataType STTop(ST* ps)
{
    assert(ps);
    assert(ps->top > 0);
    return ps->a[ps->top – 1];
}

//长度计算
int STSize(ST* ps)
{
    assert(ps);

    return ps->top;
}

//判断是否为空
bool STEmpty(ST* ps)
{
    assert(ps);

    return ps->top == 0;
}

（3）Test.c

1.头文件的声明

#include “Stack.h”