Cousins in Binary Tree Problem & Solution

Given the `root` of a binary tree with unique values and the values of two different nodes of the tree `x` and `y`, return `true` if the nodes corresponding to the values `x` and `y` in the tree are cousins, or `false` otherwise.

Two nodes of a binary tree are cousins if they have the same depth with different parents.

Note that in a binary tree, the `root` node is at the depth `0`, and children of each depth `k` node are at the depth `k + 1`.

C++ Solution

``````#pragma GCC optimize("Ofast")
#pragma GCC optimization("max-inline-insns-recursive-auto")

static const int _=[](){std::ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);return 0;}();

/**
* struct TreeNode {
*   int val;
*   TreeNode *left;
*   TreeNode *right;
*   TreeNode() : val(0), left(nullptr), right(nullptr) {}
*   TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
*   TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class Solution {
public:
bool isCousins(TreeNode* root, int x, int y) {

return left.depth == right.depth &&
left.parent != right.parent;
}

private:
TreeNode* parent;
int depth;
};

if (root == nullptr) {
return {nullptr, 0};
}

if (root->left && root->left->val == val) {
return {root, depth + 1};
}

if (root->right && root->right->val == val) {
return {root, depth + 1};
}