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

class Solution {
public:
    TreeNode* mergeTrees(TreeNode* t1, TreeNode* t2) {
        if(!t1&&!t2){
            return 0;
        }
        TreeNode *root=new TreeNode(0);
        if(t1)
            root->val+=t1->val;
        if(t2)
            root->val+=t2->val;
        root->left=mergeTrees(t1?t1->left:0,t2?t2->left:0);
        root->right=mergeTrees(t1?t1->right:0,t2?t2->right:0);
        return root;
    }
};