可以用卡特兰数做 以下分析转自:http://www.cnblogs.com/kevinACMer/p/3724640.html?utm_source=tuicool 这道题之前自己做的时候并没有反应过来是求卡特兰数,当时是按递推来想的.后来查了下HDU4165,结果一看大标题就说是卡特兰数,自己想了想, 还真是那么回事.主要还是对于卡特兰数用的不多,也就当时没立马反应过来了.下面介绍这道题我的思路,然后对卡特兰数再做一些补充. 本题题意:罐子里有N片相同的药片,开始的时候药片都是完整的一整片.…

Man Down Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 2030    Accepted Submission(s): 743 Problem Description The Game “Man Down 100 floors” is an famous and interesting game.You can enjoy t…

给出点集,和不大于L长的绳子,问能包裹住的最多点数. 考虑每个点都作为左下角的起点跑一遍极角序求凸包,求的过程中用DP记录当前以j为当前末端为结束的的最小长度,其中一维作为背包的是凸包内侧点的数量.也就是 dp[j][k]代表当前链末端为j,其内部点包括边界数量为k的最小长度.这样最后得到的一定是最优的凸包. 然后就是要注意要dp[j][k]的值不能超过L,每跑一次凸包,求个最大的点数量就好了. 和DP结合的计算几何题,主要考虑DP怎么搞 /** @Date : 2017-09-27 17:27…

Pills Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Problem Description Aunt Lizzie takes half a pill of a certain medicine every day. She starts with a bottle that contains N pills. On the first day, she removes…

B - Monkey and Banana Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u Submit Status Practice HDU 1069 Appoint description: Description A group of researchers are designing an experiment to test the IQ of a monkey. They wi…

G - FatMouse's Speed Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u Submit Status Practice HDU 1160 Appoint description: Description FatMouse believes that the fatter a mouse is, the faster it runs. To disprove this, you…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4826 思路:dp[x][y][d]表示从方向到达点(x,y)所能得到的最大值,然后就是记忆化了. #include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #define REP(i, a, b) for (int i = (a); i < (b); ++i)…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=2861 题目大意:n个位置,m个人,分成k段,统计分法.S(n)=∑nk=0CknFibonacci(k) 解题思路: 感觉是无聊YY出的DP,数据目测都卡了几W组.如果不一次打完,那么直接T.$DP[i][j][k][0|1]$ 用$DP[i][j][k][0|1]$表示,$i$位置,已经安排了$j$个人,有$k$段,且$i$位置不放人/放人. 边界 $DP[0][0][0][0]=DP[0][0]…

Reference: http://blog.csdn.net/me4546/article/details/6333225 题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=2838 题目大意:每头牛有个愤怒值,每次交换相邻两个数进行升序排序,$cost=val_{1}+val_{2}$,求$\min \sum cost_{i}$ 解题思路: 按输入顺序DP: 第i的值val的最小cost=当前数的逆序数个数*val+当前数的逆序数和 相当于每次只…

hdu 5791 Two Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 1421    Accepted Submission(s): 630 Problem Description Alice gets two sequences A and B. A easy problem comes. How many pair of sequ…