题意:每个人有一个DI值,现在有一个小黑屋,这些人的顺序可以利用这个小黑屋调整,调整方式是入栈出栈方式,也就是说,这里的方案是有卡特兰数个方式. 调整后使得 d1*0 + d2*1 + d3*2 + d4*3 ...... 最小. 分析:这个题目竟然会是区间DP. 考虑区间 [ L, R ] ,那么L,可以从任意位置出栈,枚举出栈位置,可以划分为两个部分,也就是说两个子问题,但是如何利用这两个子问题得到 d[L,R], d[L,R] = 前一部分 + D[L]*(i-L) + 后一部分 + 后一…

Problem Description Teacher Mai has n numbers a1,a2,⋯,anand n−1 operators("+", "-" or "*")op1,op2,⋯,opn−1, which are arranged in the form a1 op1 a2 op2 a3 ⋯ an.He wants to erase numbers one by one. In i-th round, there are n+…

Problem Description The TV shows such as You Are the One has been very popular. In order to meet the need of boys who are still single, TJUT hold the show itself. The show is hold in the Small hall, so it attract a lot of boys and girls. Now there ar…

Dire Wolf Time Limit: 5000/5000 MS (Java/Others)    Memory Limit: 512000/512000 K (Java/Others)Total Submission(s): 3815    Accepted Submission(s): 2266 Problem Description Dire wolves, also known as Dark wolves, are extraordinarily large and powerfu…

题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=5568 题意: 求所有长度为k的严格升序子序列的个数. 题解: 令dp[i][k]表示以i结尾的长度为k的所有严格升序子序列的个数,则有状态转移:dp[i][k]+=dp[j][k-1](其中,arr[i]>arr[j],并且i>j): 最后答案为dp[1][k]+...dp[n][k]. 代码: import java.util.*; import java.math.*; public cla…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4597 #include <cstdio> #include <cstring> #include <iostream> #include <cmath> #include <algorithm> #include <queue> #include <vector> using namespace std; ; ; const…

Cake slicing Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 149    Accepted Submission(s): 86 Problem Description A rectangular cake with a grid of m*n unit squares on its top needs to be slice…

题目:http://acm.hdu.edu.cn/showproblem.php?pid=5181 题解:https://www.cnblogs.com/Miracevin/p/10960717.html 原来卡特兰数的这个问题还能区间DP…… XO #include<cstdio> #include<cstring> #include<algorithm> #define ll long long using namespace std; int rdn() { ;;…

题目链接 http://acm.split.hdu.edu.cn/showproblem.php?pid=4283 Problem Description The TV shows such as You Are the One has been very popular. In order to meet the need of boys who are still single, TJUT hold the show itself. The show is hold in the Small…

题目链接 http://acm.split.hdu.edu.cn/showproblem.php?pid=4293 Problem Description After the regional contest, all the ACMers are walking alone a very long avenue to the dining hall in groups. Groups can vary in size for kinds of reasons, which means, sev…