C语言链式队列的插入，取出，删除

链队列的基本操作

用结构体形成链，进行队列的基本操作

代码：

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

typedef int ElemType;

typedef struct queue
{
     
    ElemType data;
    struct queue *next;
} queue;

queue *head, *end;

void seqlistinit();
void push();
void printmenu();
ElemType pop();
ElemType gettop();
int isempty();
void destroy();

void printmenu()
{
     
    int m;
    printf("--------------------\n");
    printf("please input your operation:\n", &m);
    printf("1.push\n");
    printf("2.pop\n");
    printf("3.get top\n");
    printf("4.break and destroy\n");
    printf("--------------------\n");
}

void seqlistinit()
{
     
    head = (queue *)malloc(sizeof(queue));
    head->next = NULL;
    end = head;
}

int isempty()
{
     
    if (head == end)
        return 1;
    else
        return 0;
}

void push()
{
     
    int m;
    queue *q;
    q = (queue *)malloc(sizeof(queue));
    q->next = NULL;
    printf("please input the number you want\n");
    scanf("%d", &m);
    q->data = m;

    end->next = q;
    end = q;
    int k = end->data;
    printf("%d insert Succss!\n", k);
}

ElemType pop()
{
     
    if (isempty())
    {
     
        printf("queue is empty\n");
        return 0;
    }
    else
    {
     
        queue *q = head->next;
        head->next = q->next;
        ElemType a = q->data;
        printf("%d pop success!\n", a);
        head->next = q->next;
        if (end == q)
            end = head;
        free(q);
        return a;
    }
}

ElemType gettop()
{
     
    if (isempty())
    {
     
        printf("queue is empty\n");
        return 0;
    }
    else
    {
     
        ElemType a = head->next->data;
        printf("%d is the top data!\n", a);
        return a;
    }
}

void destroy()
{
     
    queue *q;
    while (end != head)
    {
     
        q = head;
        head = head->next;
        free(q);
    }

    printf("destroy successful\n");
}

int main()
{
     
    seqlistinit();
    int n, m;
    int flag = 1;
    while (flag)
    {
     
        printmenu();
        scanf("%d", &m);
        switch (m)
        {
     
        case 1:
            push();
            break;
        case 2:
            pop();
            break;
        case 3:
            gettop();
            break;
        case 4:
            destroy();
            flag = 0;
            break;
        default:
            printf("please input again\n");
            break;
        }
    }
}