abc184
A - Determinant
题意
求二阶行列式
题解
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B - Quizzes
题意
给n个问题,和答题情况,答对加1,答错减1(为0不扣分),初始分数x,求最终分数
求二阶行列式
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给n个问题,和答题情况,答对加1,答错减1(为0不扣分),初始分数x,求最终分数
与视觉slam有关的群
三维旋转矩阵构成了特殊正交群(special orthogonal group)
$$S O(3)=\left\{R \in \mathbb{R}^{3 \times 3} \mid R R^{T}=I, \operatorname{det}(R)=1\right\}$$
三维变换矩阵构成了特殊欧氏群(special euclidean group)
$$SE(3)=\left\{T=\left[\begin{array}{cc}R & t \\0^{T} & 1\end{array}\right] \in \mathbb{R}^{4 \times 4} \mid R \in SO(3), t \in \mathbb{R}^{3}\right\} $$
内积
外积
定义 ^ 符号
euclidean transform
同一个向量在两个坐标系中的表示,坐标系的变换包括一次旋转和一次平移
很早就想写cmake,但是一直懒得写
今天也随便写点cmake
官方对cmake的解释
CMake is an open-source, cross-platform family of tools designed to build, test and package software. CMake is used to control the software compilation process using simple platform and compiler independent configuration files, and generate native makefiles and workspaces that can be used in the compiler environment of your choice. The suite of CMake tools were created by Kitware in response to the need for a powerful, cross-platform build environment for open-source projects such as ITK and VTK.
对于一个数列,每次操作交换相邻的两个数,问是否需要达到n(n-1)/2次操作才可以让数列递增
判断数列是否严格单调递减
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给一数列,判断有多少对数满足 x & y >= x ^ y
错排公式
Dn = floor(n!/e + 0.5) = (n - 1) * (Dn-1 + Dn-2)
D1 = 0 , D2 = 1
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必装环境 python, requests
推荐环境 anaconda, pycharm
定时打卡、同时多人打卡、发邮件反馈打卡信息、失败重新打卡
(为什么不用发信息,国内手机号在twilio上不能用了)
不使用
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对于一个森林,点和边对连通图个数的贡献是每个点+1,每条边-1
直接法,注意数组大小爆long long
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