FCFS,SJF（java实现）

  1 import java.io.BufferedReader;
  2 
  3 import java.io.InputStreamReader;
  4 
  5 public class FCFSANDSJF {
  6 
  7   private  static int i;
  8 
  9   private  int j;
 10 
 11   private  int temp; 
 12 
 13   private int m[];
 14 
 15   private int n[];
 16 
 17   private int process_number;//进程数
 18 
 19   private int arrival_time[];//到达时间
 20 
 21   private int services_time[];//服务时间
 22 
 23   private int start_time[];//开始时间
 24 
 25   private int completion_time[];//完成时间
 26 
 27   private int turn_around_time[];//周转时间
 28 
 29   private double add1;
 30 
 31   private double add2;
 32 
 33   private double add3;
 34 
 35   private double add4;
 36 
 37   private double right_turn_around_time[];
 38 
 39 private void FCFS(){
 40 
 41  System.out.println("\n===FCFS先来先服务算法===");
 42 
 43  System.out.println("\n到达时间是：");
 44 
 45  for(i=0;i<process_number;i++){
 46 
 47   System.out.print(arrival_time[i]+"\t");
 48 
 49  }
 50 
 51  System.out.println("\n服务时间是：");
 52 
 53  for(i=0;i<process_number;i++){
 54 
 55   System.out.print(services_time[i]+"\t");
 56 
 57  }
 58 
 59  System.out.println("\n开始时间是：");
 60 
 61  for(i=0;i<process_number;i++){
 62 
 63   n[i]=arrival_time[i];
 64 
 65   m[i]=i;
 66 
 67  }
 68 
 69  for(i=0;i<process_number-1;i++){
 70 
 71   for(j=i+1;j<process_number;j++){
 72 
 73    if(n[i]>n[j]){
 74 
 75     temp=n[i];
 76 
 77     n[i]=n[j];
 78 
 79     n[j]=temp;
 80 
 81     temp=m[i];
 82 
 83     m[i]=m[j];
 84 
 85     m[j]=temp;
 86 
 87    }
 88 
 89   }
 90 
 91  }
 92 
 93  start_time[m[0]]=arrival_time[m[0]];
 94 
 95  for(i=1;i<process_number;i++){
 96 
 97   if(arrival_time[m[i]]<start_time[m[i-1]]+services_time[m[i-1]])
 98 
 99    start_time[m[i]]=start_time[m[i-1]]+services_time[m[i-1]];
100 
101   else
102 
103    start_time[m[i]]=arrival_time[m[i]];
104 
105  }
106 
107  for(i=0;i<process_number;i++){
108 
109    System.out.print(start_time[i]+"\t");
110 
111   }
112 
113  System.out.println("\n完成时间是：");
114 
115  for(i=0;i<process_number;i++){
116 
117   completion_time[i]=start_time[i]+services_time[i];
118 
119  }
120 
121  for(i=0;i<process_number;i++){
122 
123   System.out.print(completion_time[i]+"\t");
124 
125  }
126 
127  System.out.println("\n周转时间是：");
128 
129  for(i=0;i<process_number;i++){
130 
131   turn_around_time[i]=completion_time[i]-arrival_time[i];
132 
133  }
134 
135  for(i=0;i<process_number;i++){
136 
137   System.out.print(turn_around_time[i]+"\t");
138 
139  }
140 
141  add1=0;
142 
143  for(i=0;i<process_number;i++){
144 
145   add1=add1+turn_around_time[i];
146 
147  }
148 
149  System.out.println("\n平均周转时间是："+add1/process_number);
150 
151  System.out.println("\n带权周转时间是：");
152 
153  for(i=0;i<process_number;i++){
154 
155   right_turn_around_time[i]=turn_around_time[i]*1.0/services_time[i];
156 
157  }
158 
159  for(i=0;i<process_number;i++){
160 
161   System.out.print(right_turn_around_time[i]+"\t");
162 
163  }
164 
165  System.out.println("\n平均带权周转时间是：");
166 
167  add2=0;
168 
169  for(i=0;i<process_number;i++){
170 
171   add2=add2+right_turn_around_time[i];
172 
173  }
174 
175  System.out.println(add2/process_number);
176 
177  
178 
179 }
180 
181 private void SJF(){
182 
183  System.out.println("\n===SJF：短作业优先算法===");
184 
185  System.out.println("\n到达时间是：");
186 
187  for(i=0;i<process_number;i++){
188 
189   System.out.print(arrival_time[i]+"\t");
190 
191  }
192 
193  System.out.println("\n服务时间是：");
194 
195  for(i=0;i<process_number;i++){
196 
197   System.out.print(services_time[i]+"\t");
198 
199  }
200 
201  System.out.println("\n开始时间是：");
202 
203  m[0]=0;
204 
205  for(i=0;i<process_number-1;i++){
206 
207   if(arrival_time[i]>arrival_time[i+1])
208 
209    m[0]=i+1;
210 
211  }
212 
213  for(i=0;i<process_number;i++){
214 
215   n[i]=services_time[i];
216 
217   m[i+1]=i;
218 
219  }
220 
221  for(i=0;i<process_number-1;i++){
222 
223   for(j=i+1;j<process_number;j++){
224 
225    if(n[i]>n[j]){
226 
227     temp=n[i];
228 
229     n[i]=n[j];
230 
231     n[j]=temp;
232 
233     temp=m[i+1];
234 
235     m[i+1]=m[j+1];
236 
237     m[j+1]=temp;
238 
239    }
240 
241   }
242 
243  }
244 
245  for(i=1;i<process_number+1;i++){
246 
247   if(m[0]==m[i]){
248 
249    for(j=i;j<process_number;j++){
250 
251     m[j]=m[j+1];
252 
253    }
254 
255   }
256 
257  }
258 
259  start_time[m[0]]=arrival_time[m[0]];
260 
261  for(i=1;i<process_number;i++){
262 
263   if(arrival_time[m[i]]<start_time[m[i-1]]+services_time[m[i-1]])
264 
265    start_time[m[i]]=start_time[m[i-1]]+services_time[m[i-1]];
266 
267   else
268 
269    start_time[m[i]]=arrival_time[m[i]];
270 
271  }
272 
273  for(i=0;i<process_number;i++){
274 
275    System.out.print(start_time[i]+"\t");
276 
277  }
278 
279  System.out.println("\n完成时间是：");
280 
281  for(i=0;i<process_number;i++){
282 
283   completion_time[i]=start_time[i]+services_time[i];
284 
285  }
286 
287  for(i=0;i<process_number;i++){
288 
289   System.out.print(completion_time[i]+"\t");
290 
291  }
292 
293  System.out.println("\n周转时间是：");
294 
295  for(i=0;i<process_number;i++){
296 
297   turn_around_time[i]=completion_time[i]-arrival_time[i];
298 
299  }
300 
301  for(i=0;i<process_number;i++){
302 
303   System.out.print(turn_around_time[i]+"\t");
304 
305  }
306 
307  add3=0;
308 
309  for(i=0;i<process_number;i++){
310 
311   add3=add3+turn_around_time[i];
312 
313  }
314 
315  System.out.println("\n平均周转时间是："+add3/process_number);
316 
317  System.out.println("\n带权周转时间是：");
318 
319  for(i=0;i<process_number;i++){
320 
321   right_turn_around_time[i]=turn_around_time[i]*1.0/services_time[i];
322 
323  }
324 
325  for(i=0;i<process_number;i++){
326 
327   System.out.print(right_turn_around_time[i]+"\t");
328 
329  }
330 
331  System.out.println("\n平均带权周转时间是：");
332 
333  add4=0;
334 
335  for(i=0;i<process_number;i++){
336 
337   add4=add4+right_turn_around_time[i];
338 
339  }
340 
341  System.out.println(add4/process_number);
342 
343 }
344 
345 public static void main(String[] args) throws Exception{
346 
347  System.out.println("请输入进程数：");
348 
349  FCFSANDSJF wo=new FCFSANDSJF();
350 
351  BufferedReader buf=null;
352 
353  buf=new BufferedReader(new InputStreamReader(System.in));
354 
355  String str1=null;
356 
357  str1=buf.readLine();
358 
359  wo.process_number=Integer.parseInt(str1);
360 
361  wo.arrival_time=new int[wo.process_number];
362 
363  wo.services_time=new int[wo.process_number];
364 
365  wo.start_time=new int[wo.process_number+1];
366 
367  wo.completion_time=new int[wo.process_number+1];
368 
369  wo.turn_around_time=new int[wo.process_number+1];
370 
371  wo.right_turn_around_time=new double[wo.process_number+1];
372 
373  wo.m=new int[wo.process_number+1];
374 
375  wo.n=new int[wo.process_number];
376 
377  String str=null;
378 
379  String str2=null;
380 
381  System.out.println("\n请输入各进程到达时间");
382 
383  for(i=0;i<wo.process_number;i++){
384 
385   str=buf.readLine();
386 
387   wo.arrival_time[i]=Integer.parseInt(str);
388 
389  }
390 
391  System.out.println("\n请输入各个进程服务时间");
392 
393  for(i=0;i<wo.process_number;i++){
394 
395   str2=buf.readLine();
396 
397   wo.services_time[i]=Integer.parseInt(str2);
398 
399  }
400 
401  System.out.println("该进程数为"+wo.process_number);
402 
403  System.out.println("\n到达时间为");
404 
405  for(i=0;i<wo.process_number;i++){
406 
407   System.out.print(wo.arrival_time[i]+"\t");
408 
409  }
410 
411  System.out.println("\n服务时间为：");
412 
413  for(i=0;i<wo.process_number;i++){
414 
415   System.out.print(wo.services_time[i]+"\t");
416 
417  }
418 
419  System.out.println("\n======先来先服务【0】========");
420 
421  System.out.println("\n======短作业优先【1】========");
422 
423  System.out.println("\n======退出系统【2】========");
424 
425  String str3=null;
426 
427  str3=buf.readLine();
428 
429  i=Integer.parseInt(str3);
430 
431  while(i!=2){
432 
433   switch(i){
434 
435   case 0:
436 
437    wo.FCFS();
438 
439    break;
440 
441   case 1:
442 
443    wo.SJF();
444 
445    break;
446 
447   default:
448 
449    System.out.println("\n输入有误，请重新输入");
450 
451   }
452 
453   System.out.println("\n======先来先服务【0】========");
454 
455   System.out.println("\n======短作业优先【1】========");
456 
457   System.out.println("\n======退出系统【2】========");
458 
459   str3=buf.readLine();
460 
461   i=Integer.parseInt(str3);
462 
463  }
464 
465  System.out.println("系统已退出！");
466 
467 } 
468 
469 }