1.前言 jdk1.8中新增加了default关键字,就是在接口中可以增加默认实现. 因为改动接口所有的实现类都要改动,所以增加了default关键字后不需要修改其他类,默认给所有实现类增加了方法. 2.冲突 一个类实现了两个接口,这两个接口都有默认的default关键字,那么程序会先执行哪一个呢? public interface A { default void hello() { System.out.println("Hello from A"); } } public int
Balanced Binary Tree Given a binary tree, determine if it is height-balanced. For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more than 1. 解法1: 1.计算每个节点的
leetcode 原题 :(即判断二叉树是否为二叉查找树) Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtree of a node contains only nodes with keys less than the node's key. The right subtree of a node
目录 1 问题描述 2 解决方案 1 问题描述 Description In order to make their sons brave, Jiajia and Wind take them to a big cave. The cave has n rooms, and one-way corridors connecting some rooms. Each time, Wind choose two rooms x and y, and ask one of their little
采用递归和三目表达式注意红色字体一定不能写成n-- 1 package com.hunag; public class Sum { static int sum; public static int isum(int n) { sum+=n; sum=n==0?sum:isum(--n); System.out.println(n); return sum; } public static void main(String[] args) { isum(100); System.out.prin
本文内容: 判断结构 if 选择结构 switch 循环结构 while do-while for for each break.continue return 首发时间:2017-06-22 21:34 修改时间: 2018-03-16 17:01 判断结构: java中使用if作为判断结构 if语句有三种格式: package study.program_struct; import java.util.Scanner; public class if_useage { public sta