leetCode167|合并二叉树

示例 1:

输入: 
	Tree 1                     Tree 2                  
          1                         2                             
         / \                       / \                            
        3   2                     1   3                        
       /                           \   \                      
      5                             4   7                  
输出: 
合并后的树:
	     3
	    / \
	   4   5
	  / \   \ 
	 5   4   7
注意: 合并必须从两个树的根节点开始。

 

public  class MergeTreesTest2 {
    public static void main(String[] args) {
        TreeNode t1=new TreeNode(1);
        TreeNode t12=new TreeNode(3);
        TreeNode t13=new TreeNode(2);
        TreeNode t14=new TreeNode(5);
        t1.left=t12;
        t1.right=t13;
        t12.left=t14;

        TreeNode t2=new TreeNode(2);
        TreeNode t22=new TreeNode(1);
        TreeNode t23=new TreeNode(3);
        TreeNode t24=new TreeNode(4);
        TreeNode t25=new TreeNode(7);
        t2.left=t22;
        t2.right=t23;
        t22.right=t24;
        t23.right=t25;
        TreeNode treeNode = mergeTrees(t1, t2);
        System.out.println("treeNode = " + treeNode);


    }

    public static  TreeNode mergeTrees(TreeNode t1, TreeNode t2) {
        if (t1 == null && t2 == null) {
            return null;
        }
        if (t1 == null) {
            return t2;
        }
        if (t2 == null) {
            return t1;
        }
        TreeNode root = new TreeNode(t1.val + t2.val);
        root.left = mergeTrees(t1.left, t2.left);
        root.right = mergeTrees(t1.right, t2.right);
        return root;
    }
}