Delete Leaves With a Given Value

给一个二叉树和一个target, 删除所有leaf的值为target.

先找到leaf, 然后再看target

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode() {}
 *     TreeNode(int val) { this.val = val; }
 *     TreeNode(int val, TreeNode left, TreeNode right) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */
class Solution {
    public TreeNode removeLeafNodes(TreeNode root, int target) {  
        if(root == null)
            return null;
        root.left = removeLeafNodes(root.left, target);
        root.right = removeLeafNodes(root.right, target);
        if(root.left == null &&  root.right == null && root.val == target)
            root = null;
        return root;
    } 
}

/**

* Definition for a binary tree node.

* public class TreeNode {

* int val;

* TreeNode left;

* TreeNode right;

* TreeNode() {}

* TreeNode(int val) { this.val = val; }

* TreeNode(int val, TreeNode left, TreeNode right) {

* this.val = val;

* this.left = left;

* this.right = right;

* }

class Solution {

public TreeNode removeLeafNodes(TreeNode root, int target) {

if(root == null)

return null;

root.left = removeLeafNodes(root.left, target);

root.right = removeLeafNodes(root.right, target);

if(root.left == null && root.right == null && root.val == target)

root = null;

return root;

}

Delete Leaves With a Given Value

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这青苔碧瓦堆, 俺曾睡风流觉, 将五十年兴亡看饱.

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