A. Calculating Function time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output For a positive integer n let's define a function f: f(n) =  - 1 + 2 - 3 + .. + ( - 1)nn Your task is to calculate f(n…

A. The New Year: Meeting Friends time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output There are three friend living on the straight line Ox in Lineland. The first friend lives at the point x1, t…

A. Memory and Crow time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output There are n integers b1, b2, ..., bn written in a row. For all i from 1 to n, values ai are defined by the crows performi…

A. Calculating Function Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/486/problem/A Description For a positive integer n let's define a function f: f(n) =  - 1 + 2 - 3 + .. + ( - 1)nn Your task is to calculate f(n) for a…

B. OR in Matrix   Let's define logical OR as an operation on two logical values (i. e. values that belong to the set {0, 1}) that is equal to 1 if either or both of the logical values is set to 1, otherwise it is 0. We can define logical OR of three…

A. Calculating Function   For a positive integer n let's define a function f: f(n) =  - 1 + 2 - 3 + .. + ( - 1)nn Your task is to calculate f(n) for a given integer n. Input The single line contains the positive integer n (1 ≤ n ≤ 1015). Output Print…

A. Night at the Museum time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Grigoriy, like the hero of one famous comedy film, found a job as a night security guard at the museum. At first night…

C. Anya and Ghosts time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Anya loves to watch horror movies. In the best traditions of horror, she will be visited by m ghosts tonight. Anya has lo…

A. Holiday Of Equality time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output In Berland it is the holiday of equality. In honor of the holiday the king decided to equalize the welfare of all citi…

Codeforces Round #277 (Div. 2) A. Calculating Function time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output For a positive integer n let's define a function f: f(n) =  - 1 + 2 - 3 + .. + ( - 1)n…