我不知道如何递归遍历给定的二叉树,只需使用树的以下方法。例如,每个TreeNode都有一个int值和一个getter TreeNode.getValue(),现在我想找到树中具有最大值的节点。请注意,树只有一个指向其currentNode的指针,您可以移动到父节点,右节点,左节点或根节点。
我的问题:
Tree tree;
public int findMaxValue() {
//how to implement this as recursive function
}
树类:
/**
* The abstract class for a tree.
* @author JK, KM
*/
public abstract class Tree {
/**
* Moves to the left child of the current node
*
* @return true if left child exists and the move was successful; otherwise
* false
*/
public abstract boolean moveToLeftNode();
/**
* Moves to the right child of the current node
*
* @return true if right child exists and the move was successful; otherwise
* false
*/
public abstract boolean moveToRightNode();
/**
* Moves to the parent of the current node
*
* @return true if parent exists and the move was successful; otherwise
* false
*/
public abstract boolean moveToParentNode();
/**
* @return true if left child exists; otherwise false
*/
public abstract boolean hasLeftNode();
/**
* @return true if right child exists; otherwise false
*/
public abstract boolean hasRightNode();
/**
* @return true if parent exists; otherwise false
*/
public abstract boolean hasParentNode();
/**
* Sets the left child of the current node
*
* @return true if successful; otherwise false (no root set)
*
*/
public abstract boolean setLeftNode(TreeNode node);
/**
* Sets the right child of the current node
*
* @return true if successful; otherwise false (no root set)
*
*/
public abstract boolean setRightNode(TreeNode node);
/**
* Sets the current node. If the tree is empty, sets the root.
*
*/
public abstract void setCurrentNode(TreeNode node);
/**
* @return the current node or null if the tree is empty
*/
public abstract TreeNode getCurrentNode();
/**
* moves to the root node of this tree
*
* @return true if there's a root; otherwise false
*/
public abstract boolean moveToRoot();
/**
* clears the whole tree, which includes deleting all nodes and the root
* node
*/
public abstract void clearTree();
答案 0 :(得分:2)
您可以递归遍历二叉树,如下所示:
public int findMaxValue() {
return max(this.node.getValue(),
this.getLeftChild().findMaxValue(),
this.getRightChild().findMaxValue());
}
实现这个给定的Tree
接口并检查叶节点是一个练习。