第二题输入其实是按层遍历。。 剑指offer上的题  public static void main(String[] args) {         Scanner sc = new Scanner(System.in);         String in = sc.nextLine();         String target = sc.nextLine();         String[] items = in.split(",");         System.out.println(Arrays.toString(items));         int index = 0;         for (int i = 1; i <= items.length; i++) {             if(items[i-1].equals(target))                 index = i;         }         if(index == 0) {System.out.println(-1);return;}         // 有右子树         if(index * 2 + 1 <= items.length){             // 找右子树的最左             int left = index * 2 + 1;             while(left * 2 <= items.length){                 left *= 2;             }             System.out.println(left);             return;         }else{ //梅子树 在判断             if(index == 1){                 System.out.println(-1);return;             }             while(index != 1) {                 int p = findP(index);                 if (isLeft(index)) { //当前是父节点的左                     System.out.println(p);                     return;                 } else { // 当前是父节点的right                     index = p;                 }             }             System.out.println(-1);         }     }     public static int findP(int index){         return index / 2;     }     public static boolean isLeft(int index){         if((index & 1) == 0)             return true;         return false;     }