鏈棧的相關操做

/*************************************************************************
    > File Name: stack.c
    > Author: heathcliff
    > Mail: ------------------------------
    > Created Time: 2016年03月31日 星期四 16時44分40秒
 ************************************************************************/
#include<stdio.h>
#include<stdlib.h>

typedef struct node_stack
{
    int data;
    struct node_stack *next;
}stack_list,*slink; 
// *slink p至關於stack_list *p 

slink top = NULL; //設置棧頂爲空,並將其置爲全局變量
int length = 0;

/*入棧*/
void push(int x)
{
    slink new;
    new = (slink) malloc (sizeof(stack_list));
    if(!new){
        printf("內存分配失敗\n");
        exit(1);
    }
    else{
        new->data = x;
        new->next = top;
        top = new;
    }
    length ++;
}

/*出棧*/
int pop()
{
    slink p; //其實這裏ｐ沒什麼用
    //可是爲了便與理解，至關於一箇中介變量
    int temp;

    p = top;
    temp = top->data;

    if(top == NULL)
        printf("棧下溢\n");
    else{
        p = p->next;
        top = p;
        length --;
    }
    free(p);

    return temp;
}

/*獲取棧頂元素*/
int get_top()
{
    int t = -1;

    if(top != NULL)
            t = top->data;
    else
        printf("棧空\n");

    return t;
}

/*打印棧中元素*/
void print()
{
    slink p;
    printf("棧中元素以下所示\n");

    p = top;
    while(p !=NULL){
        printf("[%d]",p->data);
        p = p->next;
    }
}

/*計算鏈棧的長度*/
int main(void)
{
    int i,N,judge,input,temp;

    printf("請問您要輸入多少個元素\n");
    scanf("%d",&N);

    printf("請輸入你要入棧的數：");
    for(i = 0;i<N;i++){
        scanf("%d",&input);
        push(input);
    }
    printf("\n鏈表的長度是：%d",length);
    print();


    for(i = 0;i<N;i++){
    printf("\n請問您是否要退棧？是(1)，否(0)\n");
    scanf("%d",&judge);

    if(1 == judge){
        temp = pop();
        printf("您出棧的數是：%d\n",temp);
        printf("\n鏈表的長度是：%d",length);
    }
    else if(0 == judge){
        break;
    }
    else{
        printf("請從新輸入\n");
        break;
    }
    }
}