Leaf at same level

Problem Statement

Pattern: Related: Balance Binary Tree

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Solution

class Solution
{
	// perfect node has both left and right children 
    boolean isPerfectNode (Node node) {return node.left!=null &&node.right!=null;}
    
    int height (Node root) {
        if(root == null) return 0;
        
        int left = height(root.left);
        int right = height(root.right);
        
        if (left == -1 || right == -1) return -1;
        if (isPerfectNode(root) && left != right) return -1; 
        
        return Math.max(left, right) + 1;
    }
 
    boolean check(Node root) {return height(root) != -1;}
}