https://leetcode.com/problems/same-tree/

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

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

Idea:

If both are null, we’ve gone off the end so return true If one is null and the other isn’t, there is a difference. If one has a val that isn’t equal to the other, there is a difference. Otherwise recursively call on the subtrees.

Solution:

class solution {
public:
    bool issametree(treenode* p, treenode* q) {
        if(!p and !q) return true;
        if(!p or !q) return false;
        if(p->val != q->val) return false;
        return issametree(p->left, q->left) && issametree(p->right, q->right);
    }
};

Complexity Analysis:

Time

Memory