题解 | #合并二叉树#

import java.util.*;

/*
 * public class TreeNode {
 *   int val = 0;
 *   TreeNode left = null;
 *   TreeNode right = null;
 *   public TreeNode(int val) {
 *     this.val = val;
 *   }
 * }
 */

public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param t1 TreeNode类 
     * @param t2 TreeNode类 
     * @return TreeNode类
     */
    public TreeNode mergeTrees (TreeNode t1, TreeNode t2) {
        // write code here
        if (t1 == null)
            return t2;
        if (t2 == null)
            return t1;
        TreeNode head = new TreeNode(t1.val + t2.val);
        head.left = mergeTrees(t1.left, t2.left);
        head.right = mergeTrees(t1.right, t2.right);
        return head;
    }

    
}