LRU java, java.lang.IndexOutOfBoundsException

Question

我已经看这个太久了，似乎无法解决索引越界异常。我在看什么？对于输入，我使用 3 帧，参考字符串的长度为 20，数字为 7,0,1,2,0,3,0,4,2,3,0,3,2,1,2 ,0,1,7,0,1。返回堆栈时，最终结果应该是 107：

import java.io.IOException;
import java.util.ArrayList;
import java.util.Scanner;

public class LRU {

public static void main(String[] args) throws IOException{

    int numberOfFrames =0;
    int numberOfFaults =0;
    int referenceLength =0;
    int stackSize=0;
    Scanner scanner = new Scanner(System.in);
    int lengthOfReference[];
    ArrayList<Integer> stack = new ArrayList<Integer>();

    System.out.println("Please enter a number of frames you would like to use");
    numberOfFrames = scanner.nextInt();

    System.out.println("Please enter the length of the reference string you would like to use");
    referenceLength = scanner.nextInt();

    lengthOfReference = new int[referenceLength];

    for(int j=0; j< referenceLength; j++){

    }
    System.out.println("Please enter the reference string");
    for(int i =0; i < referenceLength; i++){
        lengthOfReference[i] = scanner.nextInt();
    }

    for(int i=0; i < referenceLength; i++){

        //if stack contains the number, remove it and add it back in so it is the most recent used

        if(stack.contains(lengthOfReference[i])){
            stack.remove(lengthOfReference[i]);
            stack.add(lengthOfReference[i]);
        }

        //if the stack is the same length as the number of frames, remove the last and add new reference string

        else if(stackSize == numberOfFrames){
            stack.remove(stack.size());
            stack.add(lengthOfReference[i]);
            numberOfFaults++;
        }

        //if the stack is less than the number of frames, just add the reference string in

        else if(stack.size() < numberOfFrames){
            stack.add(lengthOfReference[i]);
            numberOfFaults++;
            stackSize++;
        }

    }

    System.out.println("Here is the final stack: ");
    for(int i =0; i< numberOfFrames; i++){
        System.out.println(stack.get(i));
    }
    System.out.println("Number of faults is: "+numberOfFaults);

}

}

Answer 1

您的 stack.remove(stack.size()) 是 remove(int index) ，预计为 0..n-1。 又一个自动装箱滥用。