Implement a function to check if a tree is balanced. For the purposes of this question, a balanced tree is defined to be a tree such that no two leaf nodes differ in distance from the root by more than one.

isBalanced

var isBalanced = function(node){
    
    var maxDepth = function(node){
        if (node === undefined){
            return 0;
        }
        return 1 + Math.max(maxDepth(node.next[0]), maxDepth(node.next[1]));
    }
    
    var minDepth = function(node){
        if (node === undefined){
            return 0;
        }
        return 1 + Math.min(minDepth(node.next[0]), minDepth(node.next[1]));
    }
    
    return (maxDepth(node) - minDepth(node) <= 1);
}

// var makeNode = function(key, value){
//     var obj = {"key": key, 
//             "value": value, 
//             "next": [],
//             visit: false};
//     return obj;
// }

// create a balanced tree
// var root = makeNode("1", "apple");
// var node1 = makeNode("2", "orange");
// var node2 = makeNode("3", "kiwi");
// root.next.push(node1);
// root.next.push(node2);
// var node1 = makeNode("4", "banana");
// var node2 = makeNode("5", "blueberry");
// root.next[0].next.push(node1);
// root.next[0].next.push(node2);
// var node1 = makeNode("6", "grape");
// var node2 = makeNode("7", "pineapple");
// root.next[1].next.push(node1);
// root.next[1].next.push(node2);


// // should be balanced
// console.log(isBalanced(root));