Walk Time Limit: 20 Sec  Memory Limit: 256 MB Description Input Output Sample Input 3 1 2 3 1 3 9 Sample Output 9 3 0 HINT Solution 其实吧,就是每次枚举一个d,重新构图,把权值是 d 的倍数的边加入.然后Dfs暴力求一遍直径L,显然 [1, L] 都可以用 d 更新. 重点是在于复杂度的证明吧,证明在上面qwq(BearChild当时不敢写qaq). Code #i…

Walk Time Limit: 30000/15000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 266    Accepted Submission(s): 183 Special Judge Problem Description I used to think I could be anything, but now I know that I couldn't d…

TAT 第一场codeforces B. Array Walk #暴力 #贪心 题目链接 题意 有\(a1, a2, ..., an\) 个格子(每个格子有各自分数),最初为1号格(初始分数为\(a1\)),支持两种走法(经过的格子分数会相应累加),只能走\(k\)步:①向右走.②向左走,但是每一次向左操作走完一格后不能再连续地向左移动,允许向左走的操作次数为\(z\).现要求你走完k次后获得的最大分数. 分析 参考了官方题解,假定我们有\(t\)次移动是向左的,那么剩下\(k-t\)次向右,我…

朗格拉日计算 Time Limit: 10 Sec  Memory Limit: 128 MB Description Input Output 仅一行一个整数表示答案. Sample Input 5 3 2 5 4 1 Sample Output 4 HINT Main idea 将一个排列围成一个环,每个点有一个值a[i],若顺时针三个点A.B.C 满足 a[A]<a[B]<a[C] 则可以统计答案,询问答案. Solution 我们不考虑环,从序列考虑,显然可以统计的就是类似这种:123…

红与蓝 Time Limit: 10 Sec  Memory Limit: 256 MB Description Input Output Sample Input 2 2 0 1 -1 -1 2 0 1 -1 1 Sample Output 1 2 -1 HINT Main idea 每个节点有红色.蓝色或者无色,给定了若干叶子节点的颜色,非叶子节点的颜色定义为所有儿子中颜色出现次数最多的一个,若一样则无色.叶子节点无色则可以染色,红色先手,蓝色接着轮流染色,最后若根为红色则胜利否则失败.胜利…

冒泡排序 Time Limit: 10 Sec  Memory Limit: 256 MB Description Input Output 仅一行一个整数表示答案. Sample Input 4 5 7 9 13 Sample Output 2 HINT Main idea 按照题意生成排列,问要几轮冒泡排序可以让其有序(从小到大). Solution 首先我们先根据冒泡排序的性质来找个规律,因为一个数前面有几个数字比它大,这个数字就会向前移动几位,然后再回到自己的位置. 那么显然就是:设x表…

LCM Walk Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 47    Accepted Submission(s): 31 Problem Description A frog has just learned some number theory, and can't wait to show his ability to hi…

Adieu l'ami. Koyomi is helping Oshino, an acquaintance of his, to take care of an open space around the abandoned Eikou Cram School building, Oshino's makeshift residence. The space is represented by a rectangular grid of n × m cells, arranged into n…

D. Vanya and Treasure 题目连接: http://www.codeforces.com/contest/677/problem/D Description Vanya is in the palace that can be represented as a grid n × m. Each room contains a single chest, an the room located in the i-th row and j-th columns contains t…

A. Recycling Bottles 题目连接: http://www.codeforces.com/contest/671/problem/A Description It was recycling day in Kekoland. To celebrate it Adil and Bera went to Central Perk where they can take bottles from the ground and put them into a recycling bin.…