检查元素是否已在Java数组中

8 月 Questions & Answers 1348

我现在正在做的项目包括从文本文件中读取单词，并将它们加载到一个数组中（最终是一个二叉树，但这将在稍后完成）。我必须将单词和单词的频率（最初为1）都加载到数组中，所以我将这两个变量都打包到了一个对象WordNode。我可以将单词加载到数组中，但是当我试图检查数组中是否已经有单词时，事情就不对劲了。如果是，我必须将频率增加1。然而，我的代码甚至没有检查单词，只是简单地添加了它（我认为它是检查变量的引用，而不是单词本身）。下面是我的main方法和WordNode类

主要方法：

public class Driver {
/////////////// fields ///////////////
public static ArrayUnorderedList<WordNode> wordArray = new ArrayUnorderedList<WordNode>();
public static LinkedBinarySearchTree<WordNode> wordTree = new LinkedBinarySearchTree<WordNode>();   //tree to hold words

/////////////// methods ///////////////
public static void main(String[] args) throws Exception {
    //ask for filename       
    BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
    System.out.println("Enter the name of the file to read from: ");
    Reader file = new FileReader(reader.readLine());

    //read file
    Scanner input = new Scanner(file);

    while(input.hasNext()) {
        //get words from file
        String word = input.next();

        //remove non-word characters and convert to lowercase
        word = word.replaceAll("\\W", "");
        word = word.toLowerCase();

        //create node
        WordNode newWord = new WordNode(word);

        //if word is already in array
        if(wordArray.contains(newWord)) {
            System.out.println("Word is already in array");

            //increment frequency by 1
            int index = wordArray.find(newWord);
            wordArray.list[index].setFrequency(wordArray.list[index].getFrequency() + 1);
            System.out.println(newWord.getWord() + newWord.getFrequency());
        } else {
            System.out.println("Word is not yet in array");

            //add word to tree
            System.out.println(newWord.getWord());
            wordArray.addToRear(newWord);
        }
    }

    //insert into tree

    //perform traversals on tree
}

WordNode类：

public class WordNode {
   protected String word;
   protected WordNode left, right;
   protected int frequency;

   /**
    * Creates a new node with the specified data.
    * @param obj the element that will become a part of the new node
    */
   WordNode(String obj) {
      word = obj;
      left = null;
      right = null;
      frequency = 1;
   }

   /**
    * Gets the word.
    * @return the word
    */
   public String getWord() {
      return word;
   }

   /**
    * Sets the word.
    * @param word the word to set
    */
   public void setWord(String word) {
      this.word = word;
   }

   /**
    * Gets the left.
    * @return the left
    */
   public WordNode getLeft() {
      return left;
   }

   /**
    * Sets the left.
    * @param left the left to set
    */
   public void setLeft(WordNode left) {
      this.left = left;
   }

   /**
    * Gets the right.
    * @return the right
    */
   public WordNode getRight() {
      return right;
   }

   /**
    * Sets the right.
    * @param right the right to set
    */
   public void setRight(WordNode right) {
      this.right = right;
   }

   /**
    * Gets the frequency.
    * @return the frequency
    */
   public int getFrequency() {
      return frequency;
   }

   /**
    * Sets the frequency.
    * @param frequency the frequency to set
    */
   public void setFrequency(int frequency) {
      this.frequency = frequency;
   }
}

ArrayList类中的一些方法：

/**
* Returns true if this list contains the specified element.
* @param target the element that the list is searched for
* @return true if the target is in the list, false if otherwise 
*/
public boolean contains(T target) {
    return (find(target) != NOT_FOUND);
}

/**
* Returns the array index of the specified element, or the
* constant NOT_FOUND if it is not found.
* @param target the element that the list will be searched for
* @return the integer index into the array containing the target element, or the NOT_FOUND constant
*/
public int find(T target) {
    int scan = 0, result = NOT_FOUND;
    boolean found = false;

    if (!isEmpty()) {
       while (!found && scan < rear) {
          if (target.equals(list[scan])) {
              found = true;
          } else {
             scan++;
          }
       }
    }

    if (found) {
       result = scan;
    }

    return result;
}

Python中文网

有 Java 编程相关的问题?

检查元素是否已在Java数组中

共 (1) 个答案

# 1 楼答案