A. Olesya and Rodion
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output
Olesya loves numbers consisting of n digits, and Rodion only likes numbers that are divisible by t. Find some number that satisfies both of them.
有若干个活动，第i个开始时间和结束时间是[Si,fi)，同一个教室安排的活动之间不能交叠，求要安排所有活动，最少需要几个教室？
C. GCD Table
time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output
The GCD table G of size n × n for an array of positive integers a of length n is defined by formula
也许今年不该参赛的….
因为暑假才刚刚调整好心态…
B. Luxurious Houses
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output
The capital of Berland has n multifloor buildings. The architect who built up the capital was very creative, so all the houses were built in one row.
As I work with students I often face the situation when if a problem doesn’t seem clear to a student at the first sight, it makes them unable to solve it. Indeed, you always hear about specific methods and techniques. But you don’t hear about how to think in order to apply them. In this note I’ll try to sum up my experience of solving programming contest problems. However, some pieces of advice will also be applicable for olympiads in mathematics and your first steps in academic research.
**序：**博弈是信息学和数学试题中常会出现的一种类型，算法灵活多变是其最大特点，而其中有一类试题更是完全无法用常见的博弈树来进行解答。 寻找必败态即为针对此类试题给出一种解题思路。
给６个矩形的长和宽（或者宽和长），问这六个矩形能否组成一个长方体．