题解 | #合并二叉树#

/**
 * struct TreeNode {
 *	int val;
 *	struct TreeNode *left;
 *	struct TreeNode *right;
 * };
 */

/**
 * 
 * @param t1 TreeNode类 
 * @param t2 TreeNode类 
 * @return TreeNode类
 */
 void ADD(struct TreeNode* t1, struct TreeNode* t2){
        t1->val+=t2->val;
        if(t1->left!=NULL&&t2->left!=NULL)
        ADD(t1->left,t2->left);
        if(t1->left==NULL&&t2->left!=NULL)
        t1->left=t2->left;
        if(t1->right!=NULL&&t2->right!=NULL)
        ADD(t1->right,t2->right);
        if(t1->right==NULL&&t2->right!=NULL)
        t1->right=t2->right;       

 }
struct TreeNode* mergeTrees(struct TreeNode* t1, struct TreeNode* t2 ) {
    // write code here
    if(t1==NULL)return t2;
    if(t2==NULL)return t1;
    if(!(t1==NULL&&t2==NULL))
    {
        ADD(t1,t2);
    }
    return t1;
}