Boostable

摘要： 1012. The Best Rank (25) To evaluate the performance of our first year CS majored students, we consider their grades of three courses only: C - C Programming Language, M - Mathematics (Calculus or Linear Algrbra), and E - English. At the mean time, we encourage students by emphasiz... 阅读全文

摘要： 1011. World Cup Betting (20) With the 2010 FIFA World Cup running, football fans the world over were becoming increasingly excited as the best players from the best teams doing battles for the World Cup trophy in South Africa. Similarly, football betting fans were putting their mon... 阅读全文

摘要： 1010. Radix (25) Given a pair of positive integers, for example, 6 and 110, can this equation 6 = 110 be true? The answer is "yes", if 6 is a decimal number and 110 is a binary number. Now for any pair of positive integers N1 and N2, your task is to find the radix of one number wh... 阅读全文

摘要： Jordan Lecture Note-3：梯度投影法 在这一节，我们介绍如何用梯度投影法来解如下的优化问题： \begin{align} \mathop{\min}&\quad f(x)\nonumber\\\mathop{s.t.}&\quad \mathbf{A}_1 x\leq b_1\no 阅读全文

摘要： 1009. Product of Polynomials (25) This time, you are supposed to find A*B where A and B are two polynomials. Input Specification: Each input file contains one test case. Each case occupies 2 lines, and each line contains the information of a polynomial: K N1 aN1 N2 aN2 ... NK aNK, ... 阅读全文

摘要： 1008. Elevator (20) The highest building in our city has only one elevator. A request list is made up with N positive numbers. The numbers denote at which floors the elevator will stop, in specified order. It costs 6 seconds to move the elevator up one floor, and 4 seconds to move d... 阅读全文

摘要： Maximal Margin Classifier Logistic Regression 与 SVM 思路的不同点：logistic regression强调所有点尽可能远离中间的那条分割线，而SVM则强调最靠近分割线的点于分割线的距离仅可能的远。定义间隔函数：$\hat{r}^{(i)}=y^{(i)}(w^\prime x^{(i)}+b)$。当$y^{(i)}=1$时，$w^\prime x^{(i)}+b>0$；当$y^{(i)}=-1$时，$w^\prime x^{(i)}+b0$。 注意，同时扩大$w,b$，那么所有点的间隔都会扩大相同倍数，这并不影响问题的求解。定义样本的 阅读全文

摘要： 1007. Maximum Subsequence Sum (25) Given a sequence of K integers { N1, N2, ..., NK }. A continuous subsequence is defined to be { Ni, Ni+1, ..., Nj } where 1 23intmain()4{5intK;6intdata[10000];7inti;8intflag;9while(scanf("%d",&K)!=EOF){10flag=0;11for(i=0;i=0)14flag=1;15}16if(flag==0). 阅读全文

摘要： 1006. Sign In and Sign Out (25) At the beginning of every day, the first person who signs in the computer room will unlock the door, and the last one who signs out will lock the door. Given the records of signing in's and out's, you are supposed to find the ones who have unlocked a... 阅读全文

摘要： 1005. Spell It Right (20) Given a non-negative integer N, your task is to compute the sum of all the digits of N, and output every digit of the sum in English. Input Specification: Each input file contains one test case. Each case occupies one line which contains an N (2#include3... 阅读全文