快乐学习

Shuffling is a procedure used to randomize a deck of playing cards. Because standard shuffling techniques are seen as weak, and in order to avoid "inside jobs" where employees collaborate with gamblers by performing inadequate shuffles, many casinos employ automatic shuffling machines.

Being unique is so important to people on Mars that even their lottery is designed in a unique way.

Given a string, you are supposed to output the length of the longest symmetric sub-string.

Zhejiang University has 40000 students and provides 2500 courses. Now given the student name lists of all the courses, you are supposed to output the registered course list for each student who comes for a query.

Given a collection of number segments, you are supposed to recover the smallest number from them.

The magic shop in Mars is offering some magic coupons. Each coupon has an integer N printed on it, meaning that when you use this coupon with a product, you may get N times the value of that product back!

This time you are asked to tell the difference between the lowest grade of all the male students and the highest grade of all the female students.

To prepare for PAT, the judge sometimes has to generate random passwords for the users. The problem is that there are always some confusing passwords since it is hard to distinguish 1 (one) from l (L in lowercase), or 0 (zero) from O (o in uppercase).

One way that the police finds the head of a gang is to check people's phone calls. If there is a phone call between A and B, we say that A and B is related.