fifo.cpp

fcfs,这是一个操作系统进程调度的先进先出调度算法

#include "iostream.h"
#define MAXLEN 3
 typedef int elemtype;
 typedef struct 
         {
           elemtype data[MAXLEN];
           int front,rear;
         }queue;
 void init(queue *sq)      //初始化队列
         {sq->front=0;
          sq->rear=0;
         }
 int enqueue(queue *sq,elemtype x)
         { 
           if((sq->rear+1)%MAXLEN==sq->front)
              {change(queue *sq,elemtype x);
              return 1;}
           else if(sq->data[sq->rear]==x)
                  {   
                    cout<<'命中'<<"";
                    disp(queue *sq);
                     return 1;
                  }
                 else
                     {
                         sq->rear=(sq->rear+1)%MAXLEN;
                         sq->data[sq->rear]=x;
                         return  1;
                      }
           }
 change(*sq,elemtype x)
          {
           if(sq->data[sq->front]==x)
               cout<<'命中'<<"";
               return 1;
            else{
                   sq->data[sq->front]=x);
                   disq(queue *sq);
                   return 1;
           }
            }
  void disp(queue *sq)
           {int s;
            cout<<"列队中元素"<<"";
             if(sq->rear>sq->front)
                for(i=sq->front+1;i<=sq->rear;i++)
                  cout<<sq->data[i]<<"";
             else {
                    for(i=sq->front+1;i<=sq->rear+MAXLEN;i++)
                    cout<sq->data[i%MAXLEN]<<"";
                    cout<<endl;
                   }
              }
void main()
        {
          queue sq;
          int i=0;
          elemtype sort[10]={1,2,1,5,4,1,3,4,0,2};
          init(&sq);
          while(i<10)
              {  enqueue(queue *sq,sort[i]);
                 i++;
              }
         }