LeedCode刷题：617.合并二叉树

合并二叉树，叶子叠加合并

创建新的root结点，一个一个的将两颗二叉树的结点叠加起来

 1 class Solution {
 2 public:
 3     TreeNode* mergeTrees(TreeNode* t1, TreeNode* t2) {
 4         if(!t1&&!t2){
 5             return 0;
 6         }
 7         TreeNode *root=new TreeNode(0);
 8         if(t1)
 9             root->val+=t1->val;
10         if(t2)
11             root->val+=t2->val;
12         root->left=mergeTrees(t1?t1->left:0,t2?t2->left:0);
13         root->right=mergeTrees(t1?t1->right:0,t2?t2->right:0);
14         return root;
15     }
16 };