棧(stack)，是一種線性儲存結構，它有以下幾個特點： 棧中資料是按照"後進先出（LIFO, Last In First Out）"方式進出棧的。 向棧中新增/刪除資料時，只能從棧頂進行操作。

基本操作 initStack(&S) destroyStack(&S) clearStack(&S) isStackEmpty(&S) getLength(&S) getTop(S, &e) pushStack(&S, e) popStack(&S, &e) stackTraverse(S, visit())

實現程式碼:

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#define status int
#define INIT_SIZE 100
#define INCRE_SIZE 10

typedef int elem;

/*		順序棧
棧頂指標(top)棧底指標(base)
後進先出(last in first out)LIFO
*/
typedef struct {
	elem *top;
	elem *base;
	int stacksize;
}SqStack;

status initStack(SqStack * stack)
{
	stack->base = (elem *)malloc(INIT_SIZE * sizeof(elem));
	if(!stack->base) exit(-2);
	stack->top = stack->base;
	stack->stacksize = INIT_SIZE;
    printf("STACK---INIT---SUCCESS\n\n");
	return 1;
}


int isStackEmpty(SqStack *stack)
{
	if(stack->top == stack->base) return 1;
    return 0;
}

status pushStack(SqStack *stack, elem e)
{
	if(stack->top - stack->base >= stack->stacksize){
		stack->base = (elem *)realloc(stack->base ,(stack->stacksize + INCRE_SIZE) * sizeof(elem));
		if(!stack->base)	exit(-2);
		printf("STACK---PUSH---SUCCESS\n\n");
		stack->top = stack->base + stack->stacksize;
		stack->stacksize += INCRE_SIZE;
	}
	*stack->top++ = e;

	return 1;
}

status getTop(SqStack *stack, elem *e)
{
	if(stack->top == stack->base){
		printf("空棧");
		return 0;
	}
	//改變e的值
	*e = *(stack->top-1);
	//返回棧頂元素
	return 1;
}
//pop刪除S的棧頂元素，並用e放回其值
status popStack(SqStack *stack, elem * e)
{
    if(!isStackEmpty(stack)){
        *e = *(--stack->top);
    }
    return 1;
}

//返回棧的長度
status getlength(SqStack *stack)
{
    return stack->top - stack->base;
}

status clearStack(SqStack *stack)
{
    stack->top = stack->base;
	return 1;
}

//銷燬棧
status destoryStack(SqStack *stack)
{
    if(!stack->base)
        free(stack->base);
    return 1;
}

//對每一個站內元素呼叫一個函式
status stackTraverse(SqStack *stack, void visit())
{
    if(!isStackEmpty(stack)){
        elem *traver = stack->top;
        while(stack->base == stack->top--){
            visit(*stack->top);
        }
        stack->top = stack->base + getlength(stack);
    }


    return 1;
}

int main(int argc, char *argv[]) {
	SqStack stack;
	initStack(&stack);      //初始化棧

	for(int i = 0; i < 101; i++){
        pushStack(&stack, i);   //入棧
	}
    printf("length = %d\n", getlength(&stack));
    for(int j = 0; j < 101; j++){
        int e;
        popStack(&stack, &e);  //出棧
        printf("%d\t", e);
    }
    printf("\n");

    if(isStackEmpty(&stack))
        printf("Stack Empty!\n");
    else
        printf("Stack is not Empty!\n");

    printf("length = %d\n", getlength(&stack));

	clearStack(&stack);     //清空棧

//  destoryStack(&stack);

	return 0;
}