链队的基本操作

//链队(带头指针)
#include <stdio.h>
#include <stdlib.h>

#define OK 1
#define TRUE 1
#define ERROR 0
#define FALSE 0

#define MAXQSIZE 1000  //最大队列长度

typedef struct elem {
  int n;
}elem;

typedef struct Qnode {   //结点
  elem data;
  Qnode* nest;
}Qnode,*QueuePtr;

typedef struct {
  QueuePtr front;  //队头指针
  QueuePtr rear;   //队尾指针
}LinkQueue;

//初始化
int InitQueue(LinkQueue &Q) {
  Q.front = Q.rear = (QueuePtr)malloc(sizeof(Qnode));
  Q.front->nest = NULL;
  Q.rear->nest = NULL;
  if (Q.front == NULL) return ERROR;
  return OK;
}

//销毁
int DestoryQueue(LinkQueue &Q) {
  if (!Q.front) return ERROR;
  QueuePtr p;
  while (Q.front) {
    p = Q.front->nest;
    free(Q.front);
    Q.front = p;
  }
  //或者直接用Q.rear
  //while(Q.front){
  //  Q.rear=Q.front->nest;
  //  free(Q.front);
  //  Q.front=Q.rear;
  //}
  return OK;
}

//添加元素(入栈)
int AddQueue(LinkQueue &Q, elem* e) {
  if (!Q.front) return ERROR;
  QueuePtr p = (QueuePtr)malloc(sizeof(Qnode));
  if (!p) return ERROR;
  p->data = *e;
  p->nest = Q.rear->nest;
  Q.rear->nest = p;
  Q.rear = p;
  return OK;
}

//删除元素(出栈)
int DeleteQueue(LinkQueue &Q, elem* e) {
  if (!Q.front || !Q.front->nest) return ERROR;
  QueuePtr p = Q.front->nest;
  Q.front->nest = p->nest;
  *e = p->data;
  free(p);
  if (!Q.front->nest) {
    Q.rear = Q.front;
  }
  return OK;
}

//取队头元素
int GetTop(LinkQueue &Q, elem* e) {
  if (!Q.front || !Q.front->nest) return ERROR;
  *e = Q.front->nest->data;
  return OK;
}

int main()
{
  return 0;
}