100. 相同的树

O(n),简单递归

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     struct TreeNode *left;
 *     struct TreeNode *right;
 * };
 */


bool isSameTree(struct TreeNode* p, struct TreeNode* q){
    if(p==NULL&&q==NULL){
        return true;
    }
    if(p==NULL||q==NULL){
        return false;
    }
    return p->val==q->val&&isSameTree(p->left,q->left)&&isSameTree(p->right,q->right);
}