@@ -0,0 +1,59 @@
+#include<vector>
+#include<algorithm>
+#include<iostream>
+#include<unordered_map>
+using namespace std;
+/**
+* Definition for a binary tree node.
+*/
+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) {
+unordered_map<int, int> depths; /* map: value -> depth */
+unordered_map<int, int> parents; /* map: value -> parent value */
+dfs(root, 0, depths, parents);
+if (depths[x] == depths[y] && parents[x] != parents[y])
+return true;
+return false;
+}
+void dfs(TreeNode* root, int depth, unordered_map<int, int>& depths, unordered_map<int, int>& parents)
+{
+if (root == nullptr) return;
+depths[root->val] = depth;
+if (root->left != nullptr)
+{
+parents[root->left->val] = root->val;
+dfs(root->left, depth + 1, depths, parents);
+}
+if (root->right != nullptr)
+{
+parents[root->right->val] = root->val;
+dfs(root->right, depth + 1, depths, parents);
+}
+return;
+}
+};
+
+// Test
+int main()
+{
+Solution sol;
+TreeNode* root = new TreeNode(1);
+root->left = new TreeNode(2);
+root->right = new TreeNode(3);
+root->left->right = new TreeNode(4);
+root->right->right = new TreeNode(5);
+auto res = sol.isCousins(root, 2, 3);
+cout << (res ? "True" : "False") << endl;
+
+return 0;
+}