<p>Given the <code>root</code> of a binary tree with unique values and the values of two different nodes of the tree <code>x</code> and <code>y</code>, return <code>true</code> <em>if the nodes corresponding to the values </em><code>x</code><em> and </em><code>y</code><em> in the tree are <strong>cousins</strong>, or </em><code>false</code><em> otherwise.</em></p>

<p>Two nodes of a binary tree are <strong>cousins</strong> if they have the same depth with different parents.</p>

<p>Note that in a binary tree, the root node is at the depth <code>0</code>, and children of each depth <code>k</code> node are at the depth <code>k + 1</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2019/02/12/q1248-01.png" style="width: 304px; height: 270px;" />
<pre>
<strong>Input:</strong> root = [1,2,3,4], x = 4, y = 3
<strong>Output:</strong> false
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2019/02/12/q1248-02.png" style="width: 334px; height: 266px;" />
<pre>
<strong>Input:</strong> root = [1,2,3,null,4,null,5], x = 5, y = 4
<strong>Output:</strong> true
</pre>

<p><strong class="example">Example 3:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2019/02/13/q1248-03.png" style="width: 267px; height: 258px;" />
<pre>
<strong>Input:</strong> root = [1,2,3,null,4], x = 2, y = 3
<strong>Output:</strong> false
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li>The number of nodes in the tree is in the range <code>[2, 100]</code>.</li>
	<li><code>1 &lt;= Node.val &lt;= 100</code></li>
	<li>Each node has a <strong>unique</strong> value.</li>
	<li><code>x != y</code></li>
	<li><code>x</code> and <code>y</code> are exist in the tree.</li>
</ul>

/**
 * 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:

TreeNode* node(TreeNode* root, int x){
    if(root==NULL)return NULL;
    if(root->val==x)return root;
    TreeNode* l= node(root->left,x);
    if(l!=0)return l;
    return node(root->right,x);
}

int level(TreeNode* root,TreeNode* x,int lev){
    if(root==NULL)return 0;
    if(root==x)return lev;
    int l=level(root->left,x,lev+1);
    if(l!=0)return l;
    return level(root->right,x,lev+1);
}

bool isSiblings(TreeNode* root, TreeNode*x, TreeNode* y){
    if(root==NULL)return false;
    return ((root->left==x && root->right==y) || (root->left==y && root->right==x) ||
    isSiblings(root->left,x,y) || isSiblings(root->right,x,y));

}

    bool isCousins(TreeNode* root, int x, int y) {
        if(root==NULL)return false;
        TreeNode* xx= node(root,x);
        TreeNode* yy= node(root,y);
        return ((level(root,xx,0)==level(root,yy,0)) && (!(isSiblings(root,xx,yy))));
    }
};
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