100. Same Tree(判断树是否相同）

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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.

 

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

 

 

 

 

class Solution {
    public boolean isSameTree(TreeNode p, TreeNode q) {
        //base case
        if(p==null || q==null) return p==null&& q==null;
        //recursion
        return p.val==q.val && isSameTree(p.left,q.left) && isSameTree(q.right,p.right);
    }
}