其实现在想起来是个巨简单的DP,模型就跟LCS很像,比赛的时候居然没想出来,在聪哥提醒下还卡了个地方 就是说给定一串n个数字的序列,可以连续合并,最终使得序列是回文的,题目也给定了合并数字所需的代价,合并一个为0,合并2个 3个..n个的代价都有 题目比较新意的地方就是回文,这也是我们要解决的主要地方,回文..其实用前缀和+后缀和就可以解决了... 用记忆化搜索写起来比较方便,每次对于求的L和R,枚举i,j,使得 L-i合并之后可以与j-R合并之后回文,然后递归处理i和j即可. #include…

Another OCD Patient Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 645    Accepted Submission(s): 238 Problem Description Xiaoji is an OCD (obsessive-compulsive disorder) patient. This mornin…

http://acm.hdu.edu.cn/showproblem.php?pid=4960 2014 Multi-University Training Contest 9 Another OCD Patient Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 181    Accepted Submission(s): 58 Pr…

Another OCD Patient Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others) Total Submission(s): 716    Accepted Submission(s): 270 Problem Description Xiaoji is an OCD (obsessive-compulsive disorder) patient. This morni…

HDU 4960 Another OCD Patient pid=4960" target="_blank" style="">题目链接 记忆化搜索,因为每一个碎片值都是正数,所以每一个前缀和后缀都是递增的,就能够利用twopointer去找到每一个相等的位置,然后下一个区间相当于一个子问题,用记忆化搜索就可以,复杂度接近O(n^2) 代码: #include <cstdio> #include <cstring> #incl…

自从做了多校,整个人都不好了,老是被高中生就算了,题老是都不懂=-=原谅我是个菜鸟,原谅我智力不行.唯一的水题. Problem Description Though ZCC has many Fans, ZCC himself is a crazy Fan of a coder, called "Memset137". It was on Codefires(CF), an online competitive programming site, that ZCC knew Mems…

Room and Moor Time Limit: 12000/6000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 263    Accepted Submission(s): 73 Problem Description PM Room defines a sequence A = {A1, A2,..., AN}, each of which is either 0…

Turn the pokers Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 108    Accepted Submission(s): 21 Problem Description During summer vacation,Alice stay at home for a long time, with nothing to…

题意很容易转化到这样的问题:在一个强连通的有向图D中是否存在这样的集合划分S + T = D,从S到T集合的边权大于从T到S集合的边权. 即D(i, j)  > B(j, i) + D(j, i).或者等价地对任意集合划分:D(i, j) <= B(j, i) + D(j, i)(*). 实际上若存在可行流f,满足:D(i, j) <= f(i, j) <= B(i, j) + D(i, j),则有对于任意割满足式(*),即可以返回"happy". 关于可行流参…

首先这是一道dp题,对题意的把握和对状态的处理是解题关键. 题目给出的范围是n在1到1e11之间,由于在裂变过称中左儿子总是父亲节点的一个非平凡约数,容易看出裂变过程只与 素数幂有关,并且显然有素数不超过11个,幂指数不超过40,实际上可以用一个大小为11的数组来等价地表示状态,状态 与其内元素顺序无关,因此可以排序,压缩后的状态不超过3000个(准确地说是2957个,通过一个简单的dfs即可统计出此结果). 以上解决了题目的规模问题. 这道题目我开始因为理解错题意wa了几次,不能通过统计儿子节…