我在我的程序中找不到我的错误，它应该在队列中添加和减去int，然后在500分钟内打印出每个队列的平均值和最大值。我不断得到一个越界异常错误但无法解决问题。任何帮助确定我的问题的地方将不胜感激！
import java.util.*;
import java.util.Random;
import java.util.LinkedList;
import java.util.ArrayList;
public class AirportQueue {
public static int longestWaitTime = 0;
public static Random rand = new Random(3);
public static int partySize;
public static Random randQueue = new Random(2);
public static Queue<Integer> airportQ1 = new LinkedList<>();
public static Queue<Integer> airportQ2 = new LinkedList<>();
public static Queue<Integer> airportQ3 = new LinkedList<>();
public static ArrayList[] minute = new ArrayList[500];
public static ArrayList[] secondMinute = new ArrayList[250];
public static ArrayList<Integer> q1 = new ArrayList(0);
public static ArrayList<Integer> q2 = new ArrayList(0);
public static ArrayList<Integer> q3 = new ArrayList(0);
public static int avgQ1 = 0;
public static int avgQ2 = 0;
public static int avgQ3 = 0;
public void airportSimulation() {
for (int i = 0; i < 500; i++) {
if ((i % 2) == 0) { // add a party to a queue each minute
if ((airportQ1.size() < airportQ2.size()) && (airportQ1.size() < airportQ3.size())) {
partySize = rand.nextInt();
airportQ1.add(partySize);
q1.add(partySize);
} else if ((airportQ2.size() < airportQ1.size()) && (airportQ2.size() < airportQ3.size())) {
partySize = rand.nextInt();
airportQ2.add(partySize);
q2.add(partySize);
} else {
partySize = rand.nextInt();
airportQ3.add(partySize);
q3.add(partySize);
}
int queueSelected = randQueue.nextInt();
if (queueSelected == 0) {
if (airportQ1.isEmpty()) {
System.out.println("The first queue is empty.");
} else {
airportQ1.remove();
}
} else if (queueSelected == 1) { // remove a party every 2 minutes
if (airportQ2.isEmpty()) {
System.out.println("The second queue is empty.");
} else {
airportQ2.remove();
}
} else {
if (airportQ3.isEmpty()) {
System.out.println("The third queue is empty.");
} else {
airportQ3.remove();
}
}
} else {
if ((airportQ1.size() < airportQ2.size()) && (airportQ1.size() < airportQ3.size())) {
partySize = rand.nextInt();
airportQ1.add(partySize);
q1.add(partySize);
} else if ((airportQ2.size() < airportQ1.size()) && (airportQ2.size() < airportQ3.size())) {
partySize = rand.nextInt();
airportQ2.add(partySize);
q2.add(partySize);
} else {
partySize = rand.nextInt();
airportQ3.add(partySize);
q3.add(partySize);
}
}
}
// num of people in queue
for (int k = 0; k < airportQ1.size(); k++) {
int q1Total = 0;
avgQ1 = (q1Total + q1.get(k)) / 500;
}
for (int k = 0; k < airportQ2.size(); k++) {
int q1Total = 0;
avgQ2 = (q1Total + q2.get(k)) / 500;
}
for (int k = 0; k < airportQ3.size(); k++) {
int q1Total = 0;
avgQ3 = (q1Total + q3.get(k)) / 500;
}
// Max value for each queue
int max1 = q1.get(0);
for (int i = 0; i < q1.size(); i++) {
int current1 = q1.get(i);
if (current1 > max1) {
max1 = current1;
}
}
int max2 = q2.get(0);
for (int i = 0; i < q2.size(); i++) {
int current2 = q2.get(i);
if (current2 > max2) {
max2 = current2;
}
}
int max3 = q3.get(0);
for (int i = 0; i < q3.size(); i++) {
int current3 = q3.get(i);
if (current3 > max3) {
max3 = current3;
}
}
System.out.println("The average number of people in the first "
+ "Airport Security queue is " + avgQ1);
System.out.println("The average number of people in the second "
+ "Airport Security queue is " + avgQ2);
System.out.println("The average number of people in the third "
+ "Airport Security queue is " + avgQ3);
System.out.println("The maximum number of people in the first "
+ "queue at any given time was " + max1);
System.out.println("The maximum number of people in the first "
+ "queue at any given time was " + max2);
System.out.println("The maximum number of people in the first "
+ "queue at any given time was " + max3);
}
public static void main(String[] args) {
AirportQueue testAirport = new AirportQueue();
testAirport.airportSimulation();
}
}
堆栈跟踪：
线程“main”中的异常java.lang.IndexOutOfBoundsException：索引：0，大小：0
at java.util.ArrayList.rangeCheck（Unknown Source）
在java.util.ArrayList.get（未知来源）
在AirportQueue.airportSimulation（AirportQueue.java:93）
在AirportQueue.main（AirportQueue.java:134）
有问题的一行：
int max1 = q1.get(0);
答案 0 :(得分：1)
解决了问题，感谢所有评论的帮助！以下是经过纠正的代码，该代码适用于分配的类。
import java.util.Random;
import java.util.LinkedList;
import java.util.ArrayList;
public class AirportQueue {
public Random rand = new Random();
public int partySize;
public Random randQueue = new Random();
public LinkedList<Integer> airportQ1 = new LinkedList<>();
public LinkedList<Integer> airportQ2 = new LinkedList<>();
public LinkedList<Integer> airportQ3 = new LinkedList<>();
public ArrayList[] minute = new ArrayList[500];
public ArrayList[] secondMinute = new ArrayList[250];
public ArrayList<Integer> q1 = new ArrayList(0);
public ArrayList<Integer> q2 = new ArrayList(0);
public ArrayList<Integer> q3 = new ArrayList(0);
public int avgQ1 = 0;
public int avgQ2 = 0;
public int avgQ3 = 0;
public int max1 = 0;
public int max2 = 0;
public int max3 = 0;
public int countQ1 = 0;
public int countQ2 = 0;
public int countQ3 = 0;
public void airportSimulation() {
int queueSelected = randQueue.nextInt(3);
//Simulate queues for 500 minutes
for (int i = 1; i < 501; i++) {
//add a party to a queue each minute
if ((i % 2) == 0) {
if ((airportQ1.size() <= airportQ2.size()) && (airportQ1.size() <= airportQ3.size())) {
partySize = rand.nextInt(4) + 1;
airportQ1.add(partySize);
q1.add(partySize);
System.out.println("Minute " + i + ": a party of " + partySize + " just entered the queue.");
} else if ((airportQ2.size() <= airportQ1.size()) && (airportQ2.size() <= airportQ3.size())) {
partySize = rand.nextInt(4) + 1;
airportQ2.add(partySize);
q2.add(partySize);
System.out.println("Minute " + i + ": a party of " + partySize + " just entered the queue.");
} else//((airportQ3.size() <= airportQ1.size()) && (airportQ3.size() <= airportQ2.size()))
{
partySize = rand.nextInt(4) + 1;
airportQ3.add(partySize);
q3.add(partySize);
System.out.println("Minute " + i + ": a party of " + partySize + " just entered the queue.");
}
//remove a party every 2 minutes
if (queueSelected == 0) {
if (airportQ1.size() != 0) {
airportQ1.remove();
if (airportQ1.size() > 0) {
System.out.println("Minute " + i + ": a party of " + airportQ1.get(airportQ1.size() - 1) + " just passed security.");
}
}
} else if (queueSelected == 1) {
if (airportQ2.size() != 0) {
airportQ2.remove();
if (airportQ2.size() > 0) {
System.out.println("Minute " + i + ": a party of " + airportQ2.get(airportQ2.size() - 1) + " just passed security.");
}
}
} else {
if (airportQ3.size() != 0) {
airportQ3.remove();
if (airportQ3.size() > 0) {
System.out.println("Minute " + i + ": a party of " + airportQ3.get(airportQ3.size() - 1) + " just passed security.");
}
}
}
queueSelected = randQueue.nextInt(3);
} else {
if ((airportQ1.size() <= airportQ2.size()) && (airportQ1.size() <= airportQ3.size())) {
partySize = rand.nextInt(4) + 1;
airportQ1.add(partySize);
q1.add(partySize);
System.out.println("Minute " + i + ": a party of " + partySize + " just entered the queue.");
} else if ((airportQ2.size() <= airportQ1.size()) && (airportQ2.size() <= airportQ3.size())) {
partySize = rand.nextInt(4) + 1;
airportQ2.add(partySize);
q2.add(partySize);
System.out.println("Minute " + i + ": a party of " + partySize + " just entered the queue.");
} else {
partySize = rand.nextInt(4) + 1;
airportQ3.add(partySize);
q3.add(partySize);
System.out.println("Minute " + i + ": a party of " + partySize + " just entered the queue.");
}
}
//num of people in queue
int q1Total = 0;
for (int k = (airportQ1.size() - 1); k > 0; k--) {
q1Total = q1Total + airportQ1.get(k);
avgQ1 = q1Total / 500;
q1.add(q1Total);
}
int q2Total = 0;
for (int k = 1; k < airportQ2.size(); k++) {
q2Total = q2Total + q1.get(k);
q2.add(q2Total);
}
int q3Total = 0;
for (int k = 1; k < airportQ3.size(); k++) {
q3Total = q3Total + airportQ3.get(k);
q3.add(q3Total);
}
}
//avg number of people in each queue
for (int m = 1; m < q1.size(); m++) {
countQ1 = q1.get(m) + countQ1;
}
for (int m = 1; m < q2.size(); m++) {
countQ2 = q2.get(m) + countQ2;
}
for (int m = 1; m < q3.size(); m++) {
countQ3 = q3.get(m) + countQ3;
}
avgQ1 = countQ1 / (q1.size() - 1);
avgQ2 = countQ2 / (q2.size() - 1);
avgQ3 = countQ3 / (q3.size() - 1);
//Max value for each queue
for (int j = 0; j < q1.size(); j++) {
int current1 = q1.get(j);
if (current1 > max1) {
max1 = current1;
}
}
for (int i = 0; i < q2.size(); i++) {
int current2 = q2.get(i);
if (current2 > max2) {
max2 = current2;
}
}
for (int i = 0; i < q3.size(); i++) {
int current3 = q3.get(i);
if (current3 > max3) {
max3 = current3;
}
}
System.out.println("The average number of people in the first "
+ "Airport Security queue is " + avgQ1);
System.out.println("The average number of people in the second "
+ "Airport Security queue is " + avgQ2);
System.out.println("The average number of people in the third "
+ "Airport Security queue is " + avgQ3);
System.out.println("The maximum number of people in the first "
+ "queue at any given time was " + max1);
System.out.println("The maximum number of people in the second "
+ "queue at any given time was " + max2);
System.out.println("The maximum number of people in the third "
+ "queue at any given time was " + max3);
}
public static void main(String[] args) {
AirportQueue testAirport = new AirportQueue();
testAirport.airportSimulation();
}
}