sameTree用深度优先搜索判断两棵树是否相同 #算法#

·Example 1:

Input:     1         1
          / \       / \
         2   3     2   3

        [1,2,3],   [1,2,3]

Output: true

·Example 2:

Input:     1         1
          /           \
         2             2

        [1,2],     [1,null,2]

Output: false

·Example 3:

Input:     1         1
          / \       / \
         2   1     1   2

        [1,2,1],   [1,1,2]

Output: false

class Solution {
public:
    bool isSameTree(TreeNode* p, TreeNode* q) {
        if(p != NULL && q != NULL){
            if(p->val != q -> val) return false;
            return isSameTree(p->left, q->left) && isSameTree(p->right, q->right);
        }
        else if(p != NULL || q != NULL) return false;
        return true;
    }
};