117 Populating Next Right Pointers in Each Node II

将一个完整二叉树，使其每个节点都指向同层的右侧节点，初始情况下，所有的指针指向null。

递归实现，没有通过，待检查

var connect = function(root) {
    if (root === null) return 
    var p = root.next
    while(p !== null){
        if(p.left !== null){
            p = p.left
            break
        }
        if(p.right !== null){
            p = p.right
            break
        }
        p = p.next
    }
    var left = root.left
    var right = root.right
    if(left) left.next = right ? right : p
    if(right) right.next = p
    connect(left)
    connect(right)
};