CTCI 4.1

Implement a function to check if a binary tree is balanced.
For the purposes of this question, a balanced tree is defined to be a tree such that the heights of the two subtrees of any node never differ by more than one.

CTCI 4.1.java

public static boolean isBalanced(Node root){
    boolean is = false;
    if(check(root) > -1) is = true;
    return is;
}

public int check(root){
    if(root == null) return 0;
    
    int left = check(root.left);
    if(left == -1) return -1;
    
    int right = check(root.right);
    if(right == -1) return -1;
    
    if(Math.abs(left - right) > 1) return -1;
    else return Math.max(left, right) + 1;
}