java二叉樹插入函數非遞歸

Question

我已經編寫了一個代碼，用於向二叉樹插入一個元素的泛型類型，它是按其名稱排序的。不要認爲這是正確的。

public boolean insert(E e) { 
    BTNode temp = root; 
    if (root == null) { 
     root.setElement(e); 
    } 
    while (temp != null) 
    if (temp.element().getClass().getName().compareTo(e.getClass().getName()) < 0) { 
     temp = temp.getRight(); 
    } else { 
     temp = temp.getLeft(); 
    } 
    temp.setElement(e); 
    return true; 
} 

你能建議我更正嗎？

Answer 1

一種插件，需要創建一個新的節點。我現在沒有如何創建它們，因爲我沒有看到構造函數，但我建議沿着以下幾點：

public boolean insert(E e) {   
    if (root == null) { 
     root = new BTNode(); 
     root.setElement(e); //how would this work with a null root? 
     return true; //that's it, we're done (when is this ever false by the way?) 
    } 
    BTNode current = root; 
    while (true) { //brackets! indenting is important for readabilty 
     BTNode parent=current; 
     if (current.element().getClass().getName().compareTo(e.getClass().getName()) < 0) { 
      current = current.getRight(); 
      if(current==null) { //we don't have a right node, need to make one 
       current = new BTNode(); 
       parent.setRight(current); 
       break; //we have a new node in "current" that is empty 
      } 
     } else { 
      current= current.getLeft(); 
      if(current==null) { //we don't have a left node, need to make one 
       current = new BTNode(); 
       parent.setLeft(current); 
       break; //we have a new node in "current" that is empty 
      } 
     } 
    } 
    current.setElement(e); 
    return true; 
} 

Answer 2

隨着艾瑪迪斯提到的，while循環不應該有一個分號結尾：

BTNode temp = root; 
    if (root == null) { 
     root.setElement(e); 
     return; 
    } 
    while (temp != null) 
    { 
     if (temp.element().getClass().getName().compareTo(e.getClass().getName()) < 0) { 
      if(temp.getRight() != null) 
      temp = temp.getRight(); 
      else 
      { 
       temp.createRight(e); 
       temp = null; //or break 
      } 
     } else { 
      if(temp.getLeft() != null) 
      temp = temp.getLeft(); 
      else 
      { 
       temp.createLeft(e); 
       temp = null; //or break 
      } 
     } 
    } 

    return true;