sqqueue.h

#include<stdio.h>
#include<iostream>
using namespace std;
typedef int datatype;
const int maxsize = 100;
typedef struct {
	datatype data[maxsize];
	int front, rear;
}sqqueue;
void init_sqqueue(sqqueue* sq);//初始化
int empty_sqqueue(sqqueue* sq);//判队空
int gethead_sqqueue(sqqueue* sq, datatype* x);//取队头
int en_sqqueue(sqqueue* sq, datatype x);//入队
int de_sqqueue(sqqueue* sq, datatype* x);//出队

sqqueue.cpp

#include"sqqueue.h"
void init_sqqueue(sqqueue* sq) {
	sq->front = sq->rear = 0;//不能为-1
}
int empty_sqqueue(sqqueue* sq) {
	if (sq->rear == sq->front) return 1;
	else return 0;
}
int gethead_sqqueue(sqqueue* sq, datatype* x) {//队头元素值由参数返回
	if (sq->rear == sq->front) { cout << "队空，无队头可取！\n"; return 0; }
	*x = sq->data[(sq->front + 1) % maxsize];//头指针的下一个位置才是队头
	return 1;
}
int en_sqqueue(sqqueue* sq, datatype x) {
	if ((sq->rear + 1) % maxsize == sq->front)
	{
		cout << "队满，不能入队！\n"; return 0;//队满上溢
	}
	sq->rear = (sq->rear + 1) % maxsize;
	sq->data[sq->rear] = x;
	return 1;
}
int de_sqqueue(sqqueue* sq, datatype* x) {//队头元素值由参数返回
	if (sq->rear == sq->front) { cout << "队空，不能出队！\n"; return 0; }//队空下溢
	sq->front = (sq->front + 1) % maxsize;
	*x = sq->data[sq->front];
	return 1;
}