java - 我的随机搜索出了什么问题？

Question

我收到错误:“ArrayIndexOutOfBounds Exception3”我不认为这是唯一的错误，但到目前为止这就是我所能弄清楚的。

import java.util.Random;
/*class containing random search algorithm*/
public class RandomSearch {
    public static int randomSearch(int queryValue, int[] list) {
    /*conducts a random search as specified by user*/
    /*trys 10,000,000 random combinations searching
      for user value*/
    int length = list.length;
    for(int i=0; i < 10000000; i++) {
        /*generates a random number from 0 to length*/
        int randomNum = (int)Math.floor(Math.random()*(length+1));
        StdOut.print(randomNum);
        if((int)queryValue == (int)list[randomNum]) {
         return randomNum;
        }
    }
    /*returns -2 if user value not found*/
    return -2;
    }
}

Answer 1

您需要这样的东西来生成索引，这给出了 0 和长度之间的索引您生成的索引超出了数组的大小，这就是您收到索引越界异常的原因。

/*Edit - Changed val to length to match the question.*/
public int randInt(int length) {

  // Usually this can be a field rather than a method variable
  Random rand = new Random();
  int randomNum = rand.nextInt(length);
  return randomNum;
}