链式队列

#include <stdio.h>
#include <stdlib.h>
//创建初始结构体
typedef struct Queue{
    int data;
    struct Queue *next;
}Queue;
//创建队首队尾指针
typedef struct {
    Queue *first;
    Queue *last;
}OP;
//创建队列
void Init(OP *p){
    p->first = p->last = NULL;
}
//创建节点
Queue *Creat(int x){
    Queue *p;
    p = (Queue *)malloc(sizeof(Queue));
    p->data = x;
    p->next = NULL;
    return p;
}
//入队
int Enter(OP *p, int x){
    Queue *t;
    t = Creat(x);
    if(p->first == NULL && p->last == NULL) {
        p->first = p->last = t;
        return 0;
    }
    else{
        p->last->next = t;
        p->last = t;
        return 1;
    }
}
//出队
int Leave(OP *p, int *px){
    Queue *t;
    if(p->first == NULL && p->last == NULL)
        return -1;
    else if(p->first == p->last){
        *px = p->first->data;
        t = p->first;
        p->first = p->last = NULL;
        free(t);
        return 0;
    }
    else{
        *px = p->first->data;
        t = p->first;
        p->first = t->next;
        free(t);
        return 1;
    }
}
//输出整个队列
void Print(OP *p){
    while(p->first){
        printf("%d\n",p->first->data);
        p->first = p->first->next;
    }
}