homework.c

实现操作系统中的短作业优先算法C程序

#include <stdio.h>
struct sjf{
char name[10];
float arrivetime;
float servicetime;
float starttime;
float finishtime;
float zztime;
float dqzztime;
};
sjf a[100];
void input(sjf *p,int N)
{ int i;
printf("intput the process's name & arrivetime & servicetime:\nfor exmple: a 0 100\n");
for(i=0;i<=N-1;i++)
{
printf("input the %dth process's information:\n",i+1);
scanf("%s%f%f",&p[i].name,&p[i].arrivetime,&p[i].servicetime);
}

}

void Print(sjf *p,float arrivetime,float servicetime,float starttime,float finishtime,float zztime,float dqzztime,int N)
{int k;

     printf("run order:");
     printf("%s",p[0].name);
for(k=1;k<N;k++)
{printf("-->%s",p[k].name);
} 
     printf("\nthe process's information:\n");
   printf("\nname\tarrive\tservice\tstart\tfinish\tzz\tdqzz\n");
     for(k=0;k<=N-1;k++)
     { printf("%s\t%-.2f\t%-.2f\t%-.2f\t%-.2f\t%-.2f\t%-.2f\t\n",p[k].name,p[k].arrivetime,p[k].servicetime,p[k].starttime,p[k].finishtime,p[k].zztime,p[k].dqzztime);
}
   
}
//pai xu
void sort(sjf *p,int N)
{
     for(int i=0;i<=N-1;i++)
         for(int j=0;j<=i;j++)
             if(p[i].arrivetime<p[j].arrivetime)
             {
                 sjf temp;
                 temp=p[i];
                 p[i]=p[j];
                 p[j]=temp;
             }
}

//yun xing jieduan
void deal(sjf *p, float arrivetime,float servicetime,float starttime,float finishtime,float &zztime,float &dqzztime,int N)
{ int k;
    for(k=0;k<=N-1;k++)
     {
         if(k==0)
            { 
    p[k].starttime=p[k].arrivetime;
     p[k].finishtime=p[k].arrivetime+p[k].servicetime;}
         else
           {
    p[k].starttime=p[k-1].finishtime;
             p[k].finishtime=p[k-1].finishtime+p[k].servicetime;}
     }

     for(k=0;k<=N-1;k++)
     {
     p[k].zztime=p[k].finishtime-p[k].arrivetime;
     p[k].dqzztime=p[k].zztime/p[k].servicetime;
     
     }
}



void sjff(sjf *p,int N)
{float arrivetime=0,servicetime=0,starttime=0,finishtime=0,zztime=0,dqzztime=0;

sort(p,N);

        for(int m=0;m<N-1;m++)
        {if(m==0)
            p[m].finishtime=p[m].arrivetime+p[m].servicetime;
         else
            p[m].finishtime=p[m-1].finishtime+p[m].servicetime;
  
         int i=0;
         for(int n=m+1;n<=N-1;n++)
   {if(p[n].arrivetime<=p[m].finishtime)
           i++;
   }
float min=p[m+1].servicetime;
int next=m+1;//m+1=n
        for(int k=m+1;k<m+i;k++)
        {
          if(p[k+1].servicetime<min)
            {min=p[k+1].servicetime;
            next=k+1;}
            
            }
           sjf temp;
            temp=p[m+1];
            p[m+1]=p[next];
            p[next]=temp;
        }
        
   deal(p,arrivetime,servicetime,starttime,finishtime,zztime,dqzztime,N);
   
   Print(p,arrivetime,servicetime,starttime,finishtime,zztime,dqzztime,N);
}


void main()
{ int N;
   printf("------短作业优先调度算法------\n");
   printf("input the process's number:\n");
   scanf("%d",&N);

   input(a,N);
   sjf *b=a;
   sjf *c=a;
   sjff(b,N);
}