操作系统 调度算法一：采用基于静态优先级的立即抢占式调度算法

 #include <iostream.h>
#include <stdio.h>
#include <stdlib.h>
struct pcb_list
{
  int ID;
  int Priority;
  int In1;
  int In2;
  int Alltime;
  struct pcb_list *next;
  }; //PCB结构体
    pcb_list *CreatePcb()
  {
      FILE *fp;
      pcb_list *head,*s,*r;
      if((fp=fopen( "jc.txt ", "r "))==NULL) //打开文件
        {
  cout < < "Can 't open this file! " < <endl;
          exit(0);
        }
      s=(pcb_list*)malloc(sizeof(pcb_list)); //分配节点空间
      head=r=NULL;
      fscanf(fp, "%d%d%d%d%d ",&s-> ID,&s-> Priority,&s-> In1,&s-> In2,&s-> Alltime); //读文件
      while(s-> ID!=3)
      {
        if(head==NULL)head=s;
        else r-> next=s;
        r=s;
        s=(pcb_list*)malloc(sizeof(pcb_list));
        fscanf(fp, "%d%d%d%d%d ",&s-> ID,&s-> Priority,&s-> In1,&s-> In2,&s-> Alltime);
        }
        r-> next=s;r=s;
        if(r!=NULL)
          r-> next=NULL;
          fclose(fp);
        return head; //返回头指针
  }
  void Scheduling(struct pcb_list *head) //基于静态优先级的立即抢占式调度
  { pcb_list *p,*q,*r;
    p=head; q=p-> next;r=q-> next;//头节点
   
    if(p-> Priority <q-> Priority) //第一个进程的优先级小于第二个进程的优先级
    { int time1=(q-> In1*60+q-> In2)-(p-> In1*60+p-> In2);
        cout < <p-> In1 < < ": " < <p-> In2 < < "~ " < <q-> In1 < < ": " < <q-> In2 < < '0 ' < < " " < <time1 < < " " < <p-> ID < <endl;
      if(q-> Priority <r-> Priority) //第二个进程的优先级小于第三个进程的优先级
      { int time2=(r-> In1*60+r-> In2)-(q-> In1*60+q-> In2);
              int t1=(r-> In1*60+r-> In2+r-> Alltime)/60;
      int t2=(r-> In1*60+r-> In2+r-> Alltime)%60;
      cout < <q-> In1 < < ": " < <q-> In2 < < '0 ' < < "~ " < <r-> In1 < < ": " < <r-> In2 < < " " < <time2 < < " " < <q-> ID < <endl;
              cout < <r-> In1 < < ": " < <r-> In2 < < "~ " < <t1 < < ": " < <t2 < < " " < <r-> Alltime < < " " < <r-> ID < <endl;
              int t5=q-> Alltime-time2;
      int t3=(t1*60+t2+t5)/60;
      int t4=(t1*60+t2+t5)%60;
      cout < <t1 < < ": " < <t2 < < "~ " < <t3 < < ": " < <t4 < < " " < <t5 < < " " < <q-> ID < <endl;
      int t6=(p-> In1*60+p-> In2+p-> Alltime+q-> Alltime+r-> Alltime)/60;
      int t7=(p-> In1*60+p-> In2+p-> Alltime+q-> Alltime+r-> Alltime)%60;
      cout < <t3 < < ": " < <t4 < < "~ " < <t6 < < ": " < <t7 < < " " < <p-> Alltime-time1 < < " " < <p-> ID < <endl;
      }//if
      else
      { //第二个进程的优先级大于第三个进程的优先级
      int q1=(q-> In1*60+q-> In2+q-> Alltime)/60;
      int q2=(q-> In1*60+q-> In2+q-> Alltime)%60;
              //打印第二个进程的完整信息
      cout < <q-> In1 < < ": " < <q-> In2 < < '0 ' < < "~ " < <q1 < < ": " < <q2 < < " " < <q-> Alltime < < " " < <q-> ID < <endl;
                  if(p-> Priority> r-> Priority)
  { //第一个进程的优先级大于第三个进程的优先级
  int m1=(q1*60+q2+p-> Alltime-time1)/60;
  int m2=(q1*60+q2+p-> Alltime-time1)%60;
                      cout < <q1 < < ": " < <q2 < < "~ " < <m1 < < ": " < <m2 < < " " < <p-> Alltime-time1 < < " " < <p-> ID < <endl;
          int m3=(m1*60+m2+r-> Alltime)/60;
                          int m4=(m1*60+m2+r-> Alltime)%60;
      cout < <m1 < < ": " < <m2 < < "~ " < <m3 < < ": " < <m4 < < " " < <r-> Alltime < < " " < <r-> ID < <endl;
  }
  else
  { //第一个进程的优先级小于第三个进程的优先级
  int q3=(q1*60+q2+r-> Alltime)/60;
                          int q4=(q1*60+q2+r-> Alltime)%60;
                        cout < <q1 < < ": " < <q2 < < "~ " < <q3 < < ": " < <q4 < < " " < <r-> Alltime < < " " < <r-> ID < <endl;
  int t6=(p-> In1*60+p-> In2+p-> Alltime+q-> Alltime+r-> Alltime)/60;
                  int t7=(p-> In1*60+p-> In2+p-> Alltime+q-> Alltime+r-> Alltime)%60;
cout < <q3 < < ": " < <q4 < < "~ " < <t6 < < ": " < <t7 < < " " < <p-> Alltime-time1 < < " " < <p-> ID < <endl;
  }
      }//else
 
    }//if
    else if(p-> Priority <r-> Priority) //第一个进程的优先级大于第二个进程的优先级
    { // 且第一个进程的优先级小于第三个进程的优先级
        int time3=r-> In1*60+r-> In2-p-> In1*60-p-> In2;//69
        cout < <p-> In1 < < ": " < <p-> In2 < < "~ " < <r-> In1 < < ": " < <r-> In2 < < " " < <time3 < < " " < <p-> ID < <endl;
int a1=(r-> In1*60+r-> In2+r-> Alltime)/60;
        int a2=(r-> In1*60+r-> In2+r-> Alltime)%60;
cout < <r-> In1 < < ": " < <r-> In2 < < "~ " < <a1 < < ": " < <a2 < < " " < <r-> Alltime < < " " < <r-> ID < <endl;
        int a3=(a1*60+a2+p-> Alltime-time3)/60;
int a4=(a1*60+a2+p-> Alltime-time3)%60;
        cout < <a1 < < ": " < <a2 < < "~ " < <a3 < < ": " < <a4 < < " " < <p-> Alltime-time3 < < " " < <p-> ID < <endl;
int a5=(p-> In1*60+p-> In2+p-> Alltime+q-> Alltime+r-> Alltime)/60;
int a6=(p-> In1*60+p-> In2+p-> Alltime+q-> Alltime+r-> Alltime)%60;
        cout < <a3 < < ": " < <a4 < < "~ " < <a5 < < ": " < <a6 < < " " < <q-> Alltime < < " " < <q-> ID < <endl;
    }
    else
    { //第一个进程的优先级最大
    int p1=(p-> In1*60+p-> In2+p-> Alltime)/60;
            int p2=(p-> In1*60+p-> In2+p-> Alltime)%60;
    //打印第一个进程的完整信息
          cout < <p-> In1 < < ": " < <p-> In2 < < "~ " < <p1 < < ": " < <p2 < < " " < <p-> Alltime < < " " < <p-> ID < <endl;
          if(q-> Priority> r-> Priority) //第二个进程的优先级大于第三个进程的优先级
  {
  //打印第二个进程的完整信息
  int r1=(p1*60+p2+q-> Alltime)/60;
  int r2=(p1*60+p2+q-> Alltime)%60;
  cout < <p1 < < ": " < <p2 < < "~ " < <r1 < < ": " < <r2 < < " " < <q-> Alltime < < " " < <q-> ID < <endl;
  //打印第三个进程的完整信息
                  int r3=(p-> In1*60+p-> In2+p-> Alltime+q-> Alltime+r-> Alltime)/60;
  int r4=(p-> In1*60+p-> In2+p-> Alltime+q-> Alltime+r-> Alltime)%60;
  cout < <r1 < < ": " < <r2 < < "~ " < <r3 < < ": " < <r4 < < " " < <r-> Alltime < < " " < <r-> ID < <endl;
  }
  else
  { //第二个进程的优先级小于第三个进程的优先级
  int p3=(p1*60+p2+r-> Alltime)/60;
  int p4=(p1*60+p2+r-> Alltime)%60;
  //打印第三个进程的完整信息
  cout < <p1 < < ": " < <p2 < < "~ " < <p3 < < ": " < <p4 < < " " < <r-> Alltime < < " " < <r-> ID < <endl;
                  int p5=(p-> In1*60+p-> In2+p-> Alltime+q-> Alltime+r-> Alltime)/60;
  int p6=(p-> In1*60+p-> In2+p-> Alltime+q-> Alltime+r-> Alltime)%60;
  //打印第二个进程的完整信息
  cout < <p3 < < ": " < <p4 < < "~ " < <p5 < < ": " < <p6 < < " " < <q-> Alltime < < " " < <q-> ID < <endl;
  }
    }
   
  }//Scheduling
  void main()
  {pcb_list *h;
    h=CreatePcb();
    Scheduling(h);
  }