C language stack implementation

Stack related concepts

“ Stack （stack） Also known as the stack , It's an operationally constrained linear table . A linear table limited to insert and delete operations only at the end of the table . This end is called the top of the stack , relatively , Call the other end the bottom of the stack . Inserting a new element into a stack is also called a push 、 Push or push , It's putting a new element on top of the top of the stack , Make it the new top element ; Removing an element from a stack is also called making a stack or backing a stack , It removes the top element of the stack , Make its adjacent elements the new top of the stack .”

Expected stack view , Everyone should have learned the linked list , So the stack is relatively simple , I won't explain it here , Let's just show you the implementation code ！！！

Create a stack  

typedef int STDataType;
typedef struct strack
{
	STDataType* a;
	int top;
	int capacity;
}ST;

It's used here （typedef int SLTDataType;） This is to save in the stack at that time int type , Easy to modify

Initialization of stack

void StrackInit(ST* ps)
{
	assert(ps);
	ps->a = NULL;
	ps->top = ps->capacity = 0;
}

Stack insertion

void StrackPush(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)
		{
			printf("realloc fail\n");
			exit(-1);
		}
		ps->a = tmp;
		ps->capacity = newcapacity;
	}
	ps->a[ps->top] = x;
	ps->top++;
}

Stack deletion

void StrackPop(ST* ps)
{
	assert(ps);
	assert(!StrackEmpty(ps));
	ps->top--;
}

Back to top of stack element

STDataType StrackTop(ST* ps)
{
	assert(ps);
	assert(!StrackEmpty(ps));
	return ps->a[ps->top - 1];
}

Judge whether the stack is empty

bool StrackEmpty(ST* ps)
{
	assert(ps);
	return ps->top == 0;
}

The number of elements in the stack

int StrackSize(ST* ps)
{
	assert(ps);
	return ps->top - 1;
}

Destruction of the stack

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