【LeetCode】100. Same Tree（水）

Question

Given two binary trees, write a function to check if they are equal or not.

Two binary trees are considered equal if they are structurally identical and the nodes have the same value.

Code

/** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */
class Solution {
public:
    bool isSameTree(TreeNode* p, TreeNode* q) {
        if (!p && !q)   return true;
        else if (!p || !q)  return false;
        else    return (p->val == q->val && isSameTree(p->left, q->left) && isSameTree(p->right, q->right));
    }
};

更简洁的Answer：

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