B. Bear and Finding Criminals 链接:http://codeforces.com/contest/680/problem/B There are n cities in Bearland, numbered 1 through n. Cities are arranged in one long row. The distance between cities i and j is equal to |i - j|. Limak is a police officer…

A. Bear and Five Cards 题目链接:http://codeforces.com/contest/680/problem/A A little bear Limak plays a game. He has five cards. There is one number written on each card. Each number is a positive integer. Limak can discard (throw out) some cards. His go…

C. Bear and Prime 100 time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output This is an interactive problem. In the output section below you will see the information about flushing the output. Bea…

B. Bear and Finding Criminals time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output There are n cities in Bearland, numbered 1 through n. Cities are arranged in one long row. The distance betwee…

A. Bear and Five Cards time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output A little bear Limak plays a game. He has five cards. There is one number written on each card. Each number is a posit…

http://codeforces.com/contest/680/problem/E 题目大意:给你一个n*n的图,然后图上的 . (我们下面都叫做‘点’)表示可以走,X表示不能走,你有如下的操作,每次你可以选择一个k*k的框,把其中的所有的X都变成 ‘点’,问在该操作后点相连的数目最多是多少? 没看别人代码和思路自己思考并优化了好久,于是敲了两个多小时...还是代码能力太差了 思路:当然最最单纯的做法就是O(n^4).为了优化,起初想用二维树状数组+并查集的,结果发现窗口中的‘点‘’容易造成…

http://codeforces.com/contest/680/problem/D 题目大意:给你一个大小为X的空间(X<=m),在该空间内,我们要尽量的放一个体积为a*a*a的立方体,且每次放入的立方体的体积要尽可能大,问最多能放几块? 感觉自己还是太菜了...这种题目都做不来TAT 思路:因为每次都要放入,我们找一下情况以后可以发现,假设当前的体积为x,如果要让cnt个数最多,要么就是要减去x-a*a*a,要么就是让x直接等于a*a*a-1,因此我们很容易就可以得到这是一个dfs的条件,…

D. Bear and Chase 题目连接: http://codeforces.com/contest/679/problem/D Description Bearland has n cities, numbered 1 through n. There are m bidirectional roads. The i-th road connects two distinct cities ai and bi. No two roads connect the same pair of…

E. Bear and Square Grid 题目连接: http://www.codeforces.com/contest/680/problem/E Description You have a grid with n rows and n columns. Each cell is either empty (denoted by '.') or blocked (denoted by 'X'). Two empty cells are directly connected if the…

D. Bear and Tower of Cubes 题目连接: http://www.codeforces.com/contest/680/problem/D Description Limak is a little polar bear. He plays by building towers from blocks. Every block is a cube with positive integer length of side. Limak has infinitely many…