原题地址 对于给定的两个约束条件,可以通过联立方程组直接解出子序列A的和和子序列B的和,即sum(A) = (r + s) / 2,sum(B) = (r - s) / 2,假设|A|=|B|=n 所以问题变成了,在一个数组中求长度为n且子序列和为sum(A)或sum(B)有多少个. 假设count(n, s)表示长度为n且子序列和为s有多少个,则要求的是count(n, sum(A)) * count(n, sum(B)),其中1<=n<=m 或者通俗来说就是m个k-sum问题 求k-sum…

题 Today, Wet Shark is given n integers. Using any of these integers no more than once, Wet Shark wants to get maximum possible even (divisible by 2) sum. Please, calculate this value for Wet Shark. Note, that if Wet Shark uses no integers from the n …

题 There are n sharks who grow flowers for Wet Shark. They are all sitting around the table, such that sharks i andi + 1 are neighbours for all i from 1 to n - 1. Sharks n and 1 are neighbours too. Each shark will grow some number of flowers si. For i…

C. Wet Shark and Flowers time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output There are n sharks who grow flowers for Wet Shark. They are all sitting around the table, such that sharks i and i …

B. Wet Shark and Bishops time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Today, Wet Shark is given n bishops on a 1000 by 1000 grid. Both rows and columns of the grid are numbered from 1 t…

A. Wet Shark and Odd and Even time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Today, Wet Shark is given n integers. Using any of these integers no more than once, Wet Shark wants to get ma…

B. Wet Shark and Bishops time limit per test: 2 seconds memory limit per test: 256 megabytes input: standard input output: standard output Today, Wet Shark is given n bishops on a 1000 by 1000 grid. Both rows and columns of the grid are numbered from…

题目链接: http://codeforces.com/problemset/problem/621/E E. Wet Shark and Blocks time limit per test2 secondsmemory limit per test256 megabytes 问题描述 There are b blocks of digits. Each one consisting of the same n digits, which are given to you in the inp…

Today, Wet Shark is given n bishops on a 1000 by 1000 grid. Both rows and columns of the grid are numbered from 1 to 1000. Rows are numbered from top to bottom, while columns are numbered from left to right. Wet Shark thinks that two bishops attack e…

time limit per test2 seconds memory limit per test256 megabytes inputstandard input outputstandard output There are b blocks of digits. Each one consisting of the same n digits, which are given to you in the input. Wet Shark must choose exactly one d…