求方程x1+x2+x3=15的整数解的数目要求0≤x1≤5,0≤x2≤6,0≤x3≤7.解:令N为全体非负整数解(x1,x2,x3),A1为其中x1≥6的解:y1=x1-6≥0的解:A2为其中x2≥7的解:y2=x2-7≥0的解:A3为其中x3≥8的解.y3=x3-8≥0的解 A1的个数,相当于对(y1+6)+x2+x3=15求非负整数解的个数,其为C(3+9-1,9)=C(11,2) A2的个数,相当于对x1+(y2+7)+x3=15求非负整数解的个数.C(3+8-1,8)=C(10,2) A
A Simple Chess Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 2597 Accepted Submission(s): 691 Problem Description There is a n×m board, a chess want to go to the position (n,m) from the pos
Preface “Examples of designs that meet most of the criteria for "goodness" (easy to understand, flexible, efficient) are a recursive-descent parser, which is traditional procedural code. Another example is the STL, which is a generic library of
前言 论文“Reducing the Dimensionality of Data with Neural Networks”是深度学习鼻祖hinton于2006年发表于<SCIENCE >的论文,也是这篇论文揭开了深度学习的序幕. 笔记 摘要:高维数据可以通过一个多层神经网络把它编码成一个低维数据,从而重建这个高维数据,其中这个神经网络的中间层神经元数是较少的,可把这个神经网络叫做自动编码网络或自编码器(autoencoder).梯度下降法可用来微调这个自动编码器的权值,但是只有在初始化权值
题目id: 1 just print a+b give you two var a and b, print the value of a+b, just do it!! print a+b 题目id: 2 list排序 给你一个list L, 如 L=[2,8,3,50], 对L进行升序排序并输出 print sorted(L) 题目id: 3 字符串逆序 给你一个字符串 a, 如a=‘12345’,对a进行逆序输出a. print a[::-1] 题目id:4 输出字典key 给你一