我怎樣才能改變這段代碼，使我只有getKey？

Question

private void searchForK(V value , DictionaryNode<K,V> node){ 
     if(node != null){ 
      if(((Comparable<V>)value).compareTo(node.value) == 0) { 
       obtainKey = node.key; 
       return; 
      } 
      searchForK(value,node.lChild); //recursive since we have to simply look 
      searchForK(value,node.rChild);//through each child which is itself another searchforK 
     }  
    } 

public K getKey(V value) { 
    searchForK(value,rNode); 
    return obtainKey; 

}//end getKey 

如何將上述代碼更改爲getKey的函數？我對遞歸感到困惑。我想擺脫searchForK函數，並讓getKey具有與searchForK相同的功能。

這是我在改變兩個功能的嘗試：

public K getKey(V value) { 
     // private void searchForK(V value , DictionaryNode<K,V> node){ 
     if(rNode != null){ 
      if(((Comparable<V>)value).compareTo(rNode.value) == 0) { 
       obtainKey = rNode.key; 
       return (K) obtainKey; 
      } 
       rNode = rNode.lChild; 
       getKey(value); 
       rNode = rNode.rChild; 
       getKey(value); 
      } 
     return null; 

它不行爲相同的方式，雖然，我究竟做錯了什麼？

這些都是我的全局變量：

public class BinarySearchTree<K,V> implements DictionaryADT<K,V> { 
    /* data fields */ 

    /* Node Variables */ 
    public DictionaryNode<K,V> rNode; //Root Node 
    public DictionaryNode<K,V> pNode; //Parent Node 
    K obtainKey; 

我是否應該更換rNode是CURNODE在我的情況？

Answer 1

private DictionaryNode<K,V> curNode = rNode; 

public K getKey(V value) { 

    if (curNode != null) { 
     int c = ((Comparable<V>)curNode.value).compareTo(value); 

     if (c == 0) { 

       K key = curNode.key; 

       curNode = rNode; // reset curNode 
       return key; 
     } 
     else if (c < 0 && curNode.lChild != null) { 
       curNode = curNode.lChild; 
       return getKey(value); 
     } 
     else if (curNode.rChild != null) { 
       curNode = curNode.rChild; 
       return getKey(value); 
     } 
    } 
    curNode = rNode; // reset curNode 
    return null; 

}