1. // 信息结构
    2.     public static class Info{
    4.         public int nodes;
    5.         public int height;
    7.         public Info(int nodes, int height) {
    8.             this.nodes = nodes;
    9.             this.height = height;
    10.         }
    12.     }
    13.     // 判断
    14.     public static Boolean isFullMain(Node head){
    15.         if(head == null){
    16.             return null;
    17.         }
    19.         Info info = isFull(head);
    20.         return    Math.pow(2, info.height)-1 == info.nodes;
    22.     }
    24.     public static Info isFull(Node head){
    25.         if(head == null){
    26.             return new Info(0, 0);
    27.         }
    29.         // 左树要信息 右树要信息
    30.         Info leftReturn = isFull(head.left);
    31.         Info rightReturn = isFull(head.right);
    33.         // 自己也要弄信息
    34.         int nodes = 0;
    35.         int height = 0;
    36.         // 自己也算一个 一层
    37.         nodes = leftReturn.nodes + rightReturn.nodes + 1;
    38.         height = Math.max(leftReturn.height , rightReturn.height)+1;
    40.         return new Info(nodes,height);
    41.     }