数据结构与算法之循环队列的操作

//循环队列的入队和出队算法设计
#include<iostream>
#include<Windows.h>
#define MaxSize 6 //定义本循环队列的最大容量
using namespace std;
typedef struct _LQueue {    //循环队列
  int sq[MaxSize];
  int front;  //循环队列的前指针
  int rear; //循环队列的尾指针
}LqList;
//初始化循环队列
bool InitLqList(LqList *duilie) {
  if (!duilie) return false;
  duilie->front = duilie->rear = 0;
  return true;
}
//插入元素到循环队列
bool InserLq(LqList* duilie, int &Element) {
  if (!duilie) return false;
  if ((duilie->rear + 1) % MaxSize == duilie->front) {
    cout << "该队列元素已满! ";
  } else {
    duilie->sq[duilie->rear] = Element;
    duilie->rear =( duilie->rear + 1)%MaxSize;
  }
  return true;
}
//打印队列
void PrintLq(LqList *duilie) {
  if (!duilie) return;
  cout << "本循环队列的元素依次是:  ";
  int i = duilie->front;
  while (i != duilie->rear) {
    cout <<" "<< duilie->sq[i]; 
    i = (i + 1) % MaxSize;
  }
  return;
}
//获取循环队列的首元素,元素不出队
bool GetLqFirst(LqList *duilie, int &Element) {
  if (!duilie) return false;
  Element = duilie->sq[duilie->front];
  return true;
}
//出队
bool outLq(LqList *duilie,int &Element){
  if (!duilie) return false;
  if (duilie->front == duilie->rear) {
    cout << "该队列是空队列! "; 
    return false;
  } else {
    Element = duilie->sq[duilie->front];
    duilie->front = (duilie->front + 1) % MaxSize;
  }
  return true;
}
//获取循环队列元素个数
void Getlen(LqList *duilie) {
  cout << "循环队列的元素个数是:  " << (duilie->rear - duilie->front + MaxSize) % MaxSize;
  return;
}
int main(void) {
  LqList *duilie =new LqList;
  if (InitLqList(duilie)) {
    cout << "初始化循环队列成功! " << endl;
  } else {
    cout << "初始化循环队列失败! " << endl;
  }
  //循环队列入队
  int num;  //用户想要入队或者出队的个数
  cout << "请输入你想要入队的个数(本程序设置的循环队列最大容量为5): ";
  cin >> num;
  //直到用户输入正确的入队个数为止
  while (1) { 
    if (num > MaxSize) {
      cout << "输入的数量超过了本队列的最大容量,请重新输入入队的个数:  " << endl;
      cout << "请输入你想要入队的个数: ";
      cin >> num;
    } else {
      break;
    }
  }
  int Element = 0;
  for (int i = 0; i < num; i++) {
    cout << "请输入你想要插入的元素: ";
    cin >> Element;
    if (InserLq(duilie,Element)) {
      cout << "插入元素 " << Element << " 成功! " << endl;
    } else {
      cout << "插入元素失败! " << endl;
    }
  }
  //打印循环队列里的元素
  PrintLq(duilie);
  //获取循环队列的首元素,元素不出列
  if (GetLqFirst(duilie,Element)) {
    cout << "循环队列的首元素是: " << Element << endl;
  } else {
    cout << "获取循环队列首元素失败! " << endl;
  }
  //循环队列出队
  cout << "请输入你想要出队的个数: ";
  cin >> num;
  cout << endl;
  //直到用户输入正确的出队个数为止
  while (1) {
    if (num > (duilie->rear - duilie->front + MaxSize) % MaxSize) {
      cout << "输入的数量超过了本队列的最大容量,请重新输入出队的个数:  " << endl;
      cout << "请输入你想要出队的个数: ";
      cin >> num;
    } else {
      break;
    }
  }
  for (int i = 0; i < num; i++) {
    if (outLq(duilie, Element)) {
      cout << "循环队列元素出队成功! 出队元素是:   " << Element << endl;
    } else {
      cout << "循环队列元素出队失败! " << endl;
    }
  }
  PrintLq(duilie);
  Getlen(duilie);
  cout << "在入队一个元素吧,这可是循环队列哟!" << endl;
  cout << "请输入你想要插入的元素: ";
  cin >> Element;
  if (InserLq(duilie, Element)) {
    cout << "插入元素 " << Element << " 成功! " << endl;
  } else {
    cout << "插入元素失败! " << endl;
  }
  PrintLq(duilie);
  system("pause");
  return 0;
}