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leetcode257. Binary Tree Path

257. 二叉树的所有路径 - 力扣(LeetCode) Challenge: Find the problems in the answer below: # Definition for a binary tree node. # class TreeNode: # def __init

Administrator Administrator Published on 2026-01-27

Recursive Function Correctness

Contract: It is the function the son function realized, the father function rely on, and realized for the grandfather.It is so-called faith leap. But

Administrator Administrator Published on 2026-01-26

Details in leetcode

or in python have short-circuit, including many or use together. if interpreter meet a true, it will stop calculating latter conditions reversed() fun

Administrator Administrator Published on 2026-01-25

BFS in Tree

Follow tutorial 代码随想录 binary tree The most subtle algorithm here is we use size and for loop inside single while loop, we achieved traverse one layer

Administrator Administrator Published on 2026-01-24

进程

程序(Program) 是静态的指令 进程是程序的一次执行 进程被创建时,操作系统会在内核空间中创建一个PCB(Process Control Block)内容包括: 1. 分配一个唯一的PID,记录所属用户的UID 2. 分配了多少内存,正在使用什么IO设备,正在使用哪些文件 3. 进程运行情况:

Administrator Administrator Published on 2026-01-15

信号

信号的作用 实现inter process communication 的一种方式 区分 信号量(Semaphore) 实现锁 POSIX信号 信号名是信号序号的宏 即 #DEFINE SIGNIT 2 名字会被变成数字 https://man7.org/linux/man-pages/man7/s

Administrator Administrator Published on 2026-01-13

OS Q-A

difference between Ring0-3 to Linux file control access Similarity they record the Privilege/Identity of the subject (who is acting) and the Permissio

Administrator Administrator Published on 2026-01-13

SubArray Sum equals K

547. 省份数量 - 力扣(LeetCode) 图和树的bfs和dfs的区别是: DFS and BFS of map is process of spanning tree, there is not a root But for tree, usual not give us a adjace

Administrator Administrator Published on 2026-01-13

Sql Q180 Consecutive Numbers

Window Function Reference: Window Functions in SQL - GeeksforGeeks talk is cheap, example first Original table Employees Table

Administrator Administrator Published on 2026-01-04

2025回顾

这是我在北邮的第三个年头,但实际上也就过了一年多。 决定先走本科就业路线 学习内容 公开课 cs61a - cs61b开头 Csapp 第一部分 408体系 王道计算机组成原理 过了一遍 汇编语言 王爽 起了个开头 王道数据结构 过了一遍 在学校作业上花了太多时间,有点愚蠢 Java后端 Javas

Administrator Administrator Published on 2026-01-03
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