GitHub: mmdjiji/makefile-learning.

Introduction

What is makefile? Most Windows developers don’t know this, and it is useful in Linux development. Most often, the makefile directs Make on how to compile and link a program.

官方网站 | DockerHub | 清华帮助文档

本文中的Ubuntu版本为 Ubuntu 18.04 。

官方网站 | 官方文档

ROS版本介绍

本文的Ubuntu版本为 Ubuntu 18.04 ，故安装 ROS Melodic 。

官方文档 | cuda-toolkit-archive

本文使用CUDA版本为 CUDA Toolkit 10.2 ，本文的Ubuntu版本为 Ubuntu 18.04 。

Misc

【真签到题】快来看直播啦~

打开直播间，即可在直播画面内找到flag

因此flag为 HECTF{狮虎萌轻一点打出题人好吗嘤嘤嘤}

Author: JiJi, XiaoZhuo, Accelerat0r. All rights reserved.

Reverse

Welcome To Re!

下载得到一个 Signin.zip 的压缩包，解压后找到ELF文件，用ida64反编译后得到

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int __cdecl main(int argc, const char **argv, const char **envp)
{
  char s2[8]; // [rsp+0h] [rbp-70h]
  char s1; // [rsp+30h] [rbp-40h]
  unsigned __int64 v6; // [rsp+68h] [rbp-8h]
  v6 = __readfsqword(0x28u);
  strcpy(s2, "moectf{W3lc0me-T0_th3-W0rld_Of_R3v3rsE!}");
  puts("Welcome to MoeCTF! --by Reverier\nPlease Input your flag and I will check it:");
  __isoc99_scanf("%41s", &s1);
  if ( !strcmp(&s1, s2) )
    puts("Congratulations!");
  else
    puts("Ruaaaaaaaaaaaaa~~~Wrong!");
  return 0;
}

因此flag为 moectf{W3lc0me-T0_th3-W0rld_Of_R3v3rsE!}

Nezzar and Lucky Number

Nezzar's favorite digit among $1,…,9$ is $d$. He calls a positive integer lucky if $d$ occurs at least once in its decimal representation.

Nezzar and Colorful Balls

Nezzar has $n$ balls, numbered with integers $1,2,…,n$. Numbers $a_1,a_2,…,a_n$ are written on them, respectively. Numbers on those balls form a non-decreasing sequence, which means that $a_i≤a_{i+1}$ for all $1≤i<n$.

New Year's Number

Polycarp remembered the $2020$-th year, and he is happy with the arrival of the new $2021$-th year. To remember such a wonderful moment, Polycarp wants to represent the number $n$ as the sum of a certain number of $2020$ and a certain number of $2021$.

Odd Divisor

You are given an integer $n$. Check if $n$ has an odd divisor, greater than one (does there exist such a number $x$ ($x>1$) that $n$ is divisible by $x$ and $x$ is odd).