E. ZS and The Birthday Paradox 题目连接: http://www.codeforces.com/contest/711/problem/E Description ZS the Coder has recently found an interesting concept called the Birthday Paradox. It states that given a random set of 23 people, there is around 50% c…

ZS and The Birthday Paradox 题目:一年有2^n天,有k个人,他们的生日有冲突的概率是多少?答案用最简分数表示,分子分母对1e6+3取模.1 ≤ n ≤ 10^18, 2 ≤ k ≤ 10^18. 答案为 1 - A(2^n,k) / (2^n)^k,分子与分母的gcd必定为2^i.计算A(2^n,k)=(2^n) * (2^n-1) * ... * (2^n-k+1)含多少个因子2,相当于计算0~k-1中总共有多少个因子2. 因为分子乘以了模mod后就永远是0了,所以…

题目链接 http://codeforces.com/contest/711/problem/C Description ZS the Coder and Chris the Baboon has arrived at Udayland! They walked in the park where n trees grow. They decided to be naughty and color the trees in the park. The trees are numbered wit…

Coloring Trees Problem Description: ZS the Coder and Chris the Baboon has arrived at Udayland! They walked in the park where n trees grow. They decided to be naughty and color the trees in the park. The trees are numbered with integers from 1 to n fr…

D. Directed Roads 题目连接: http://www.codeforces.com/contest/711/problem/D Description ZS the Coder and Chris the Baboon has explored Udayland for quite some time. They realize that it consists of n towns numbered from 1 to n. There are n directed roads…

C. Coloring Trees 题目连接: http://www.codeforces.com/contest/711/problem/C Description ZS the Coder and Chris the Baboon has arrived at Udayland! They walked in the park where n trees grow. They decided to be naughty and color the trees in the park. The…

B. Chris and Magic Square 题目连接: http://www.codeforces.com/contest/711/problem/B Description ZS the Coder and Chris the Baboon arrived at the entrance of Udayland. There is a n × n magic grid on the entrance which is filled with integers. Chris notice…

A. Bus to Udayland 题目连接: http://www.codeforces.com/contest/711/problem/A Description ZS the Coder and Chris the Baboon are travelling to Udayland! To get there, they have to get on the special IOI bus. The IOI bus has n rows of seats. There are 4 sea…

题目链接:http://codeforces.com/problemset/problem/711/D D. Directed Roads time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output ZS the Coder and Chris the Baboon has explored Udayland for quite some…

Bus to Udayland 题目链接: http://codeforces.com/contest/711/problem/A Description ZS the Coder and Chris the Baboon are travelling to Udayland! To get there, they have to get on the special IOI bus. The IOI bus has n rows of seats. There are 4 seats in e…