栈的基本操作

#include<stdio.h>
#include<stdlib.h>

//栈结点的定义
typedef struct stacknode
{
    char data;
    struct stacknode *next;
}stacknode;

//构造空栈
stacknode* creat_stack()
{
    stacknode *top = NULL;
    return top;
}

//入栈
stacknode* push(stacknode *top, char data)  //在栈顶元素插入元素data
{
    stacknode *p = (stacknode *)malloc(sizeof(stacknode));      //生成一个新节点
    p->data = data;
    p->next = top;
    top = p;
    return top;
}

//出栈
stacknode* pop(stacknode *top, char *t)    //用t返回其值
{
    stacknode *p = NULL;
    if (top == NULL)
    {
        printf("栈为空，无法出栈！\n");
        return NULL;
    }
    *t = top->data;
    p = top;
    top = top->next;
    printf("元素%c已出栈\n", *t);
    free(p);
    return top;
}

//显示栈
void output(stacknode *top)
{
    if (top == NULL)
        printf("栈为空\n");
    else
    {
        stacknode *p = (stacknode *)malloc(sizeof(stacknode));
        p = top;
        printf("栈遍历为:");
        while(p != NULL)
        {
            printf("%c ", p->data);
            p = p->next;
        }
        free(p);
        printf("\n");
    }
}

//求栈的结点个数
void Node_count(stacknode *top)
{
    int count = 0;
    stacknode *temp = top;
    while(temp != NULL)
    {
        count++;
        temp = temp->next;
    }
    printf("栈的结点个数为%d\n", count);
}

//销毁栈
stacknode* Destroy_stack(stacknode *top)
{
    if(top == NULL)
        printf("栈为空，无法销毁!\n");
    else
    {
        stacknode *temp;
        while(top != NULL)
        {
            temp = top->next;
            free(top);
            top = temp;
        }
        printf("栈已销毁!\n");
    }
    return NULL;
}

int main()
{
    stacknode *top = creat_stack(); //建立一个空栈

    printf(" 栈子系统\n");
    printf("**************************************************\n");
    printf("* 1-----入栈 *\n");
    printf("* 2-----出栈 *\n");
    printf("* 3-----显示栈 *\n");
    printf("* 4-----求栈的结点个数 *\n");
    printf("* 5-----销毁栈 *\n");
    printf("* 0-----结束 *\n");
    printf("**************************************************\n");

    while (1)
    {
        int ch;
        printf("\n***************************************************\n");
        printf("请输入你要进行的操作对应的数字：");
        scanf("%d",&ch);
        getchar();
        switch(ch)
        {
            case 1:         //入栈
                {
                    char data;
                    printf("请输入要入栈的元素:");
                    scanf("%c", &data);
                    getchar();
                    top = push(top, data);
                    printf("元素%c已入栈\n", data);
                    break;
                }

            case 2:     //出栈
                {
                    char t = 0; //*t用来接收出栈的值;
                    top = pop(top, &t);
                    break;
                }

            case 3:         //显示栈
                {
                    output(top);
                    break;
                }
            case 4:         //求栈的结点个数
                {
                    Node_count(top);
                    break;
                }
            case 5:         //销毁栈
                {
                    top = Destroy_stack(top);
                    break;
                }
            case 0:
                {
                    printf("程序已结束!\n");
                    return 0;
                }
            default:
                {
                    printf("输入的数值有误，请重新输入\n");
                    break;
                }
        }
    }
    return 0;
}



//
// _ooOoo_
// o8888888o
// 88" . "88
// (| ^_^ |)
// O\ = /O
// ____/`---'\____
// .' \\| |// `.
// / \\||| : |||// \
// / _||||| -:- |||||- \
// | | \\\ - /// | |
// | \_| ''\---/'' | |
// \ .-\__ `-` ___/-. /
// ___`. .' /--.--\ `. . ___
// ."" '< `.___\_<|>_/___.' >'"".
// | | : `- \`.;`\ _ /`;.`/ - ` : | |
// \ \ `-. \_ __\ /__ _/ .-` / /
// ========`-.____`-.___\_____/___.-`____.-'========
// `=---='
// ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
// 佛祖保佑 永无BUG
//