先来先服务算法（FCFS java实现）

package Arithmetic;import java.io.BufferedReader;import java.io.InputStream;import java.io.InputStreamReader;import java.nio.ByteBuffer;import java.util.Scanner;import java.util.concurrent.CountDownLatch;public class Awara_OS_FCFS {public static int i;public double awara[];public double awara1[];public int process_number;public double arrival_time[];public double services_time[];public double start_time[];public double wait_time[];public double completion_time[];public double turn_around_time[];public double turn_around_time_with_weight[];private void Set_process_number(int process_nuber) {this.process_number = process_nuber;}private double get_process_number() {return process_number;}private void Set_arrival_time(int arrival_time[]) {for (i = 0; i < process_number; i++) {this.arrival_time[i] = arrival_time[i];}}private double[] get__arrival_time() {for (i = 0; i < process_number; i++) {awara[i] = arrival_time[i];}return awara;}private void Set_services_time(int services_time[]) {for (i = 0; i < process_number; i++) {this.services_time[i] = services_time[i];}}private double[] get_services_time() {for (i = 0; i < process_number; i++) {awara1[i] = services_time[i];}return awara1;}private void FCFS() {start_time[0] = arrival_time[0];completion_time[0] = arrival_time[0] + services_time[0];start_time[0] = arrival_time[0];turn_around_time[0] = completion_time[0] - arrival_time[0];turn_around_time_with_weight[0] = turn_around_time[0]/ services_time[0];for (i = 1; i < process_number; i++) {start_time[i] = completion_time[i - 1];wait_time[i] = start_time[i] - arrival_time[i];completion_time[i] = arrival_time[i] + services_time[i]+ wait_time[i];turn_around_time[i] = completion_time[i] - arrival_time[i];turn_around_time_with_weight[i] = turn_around_time[i]/ services_time[i];}System.out.println("\n：开始时间是： ");for (i = 0; i < process_number; i++) {System.out.print(start_time[i] + "\t");}System.out.println("\n等待时间是：");for (i = 0; i < process_number; i++) {System.out.print(wait_time[i] + "\t");}System.out.println("\n完成时间是：");for (i = 0; i < process_number; i++) {System.out.print(completion_time[i] + "\t");}System.out.println("\n周转时间是：");for (i = 0; i < process_number; i++) {System.out.print(turn_around_time[i] + "\t");}System.out.println("\n带权周转时间：");for (i = 0; i < process_number; i++) {System.out.print(turn_around_time_with_weight[i] + "\t");}}public static void main(String[] args) throws Exception {System.out.println("请输入进程数：");Awara_OS_FCFS cok = new Awara_OS_FCFS();BufferedReader buf = null;buf = new BufferedReader(new InputStreamReader(System.in));String str1 = null;str1 = buf.readLine();cok.process_number = (int) Double.parseDouble(str1);cok.arrival_time = new double[cok.process_number];cok.services_time = new double[cok.process_number];cok.completion_time = new double[cok.process_number + 1];cok.turn_around_time = new double[cok.process_number + 1];cok.start_time = new double[cok.process_number];cok.wait_time = new double[cok.process_number];cok.turn_around_time_with_weight = new double[cok.process_number];String str = null;String str2 = null;System.out.println("\n请输入各进程到达时间");for (i = 0; i < cok.process_number; i++) {str = buf.readLine();cok.arrival_time[i] = Double.parseDouble(str);}System.out.println("\n请输入各个进程服务时间");for (i = 0; i < cok.process_number; i++) {str2 = buf.readLine();cok.services_time[i] = Double.parseDouble(str2);}System.out.println("该进程数为" + cok.process_number);System.out.println("\n到达时间为");for (i = 0; i < cok.process_number; i++) {System.out.print(cok.arrival_time[i] + "\t");}System.out.println("\n服务时间为：");for (i = 0; i < cok.process_number; i++) {System.out.print(cok.services_time[i] + "\t");}cok.FCFS();}}