OJ题目:click here~~ 题目分析:n个人分为若干组 , 每一个人描写叙述其所在的组前面的人数和后面的人数.求这n个描写叙述中,最多正确的个数. 设dp[ i ] 为前i个人的描写叙述中最多正确的个数,则dp[ n ] 为要求的.num[ i ][ j ]  保存说前面有i个人 , 后面有j个人的人数,显然num[ i ][ j ]不超过n - i - j; 转移方程dp[ i ] = max(dp[ i ] , dp[ j ]  + num[ j ][ n - i ])  ,详解见代…

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…

模型挺好的dp题,其实这道题就是建一个模型然后就很容易想到递推过程了,我们可以把每个人的描述,存到数组a中,a[l][r]表示左边有l个,到第r个这个人所在一层停止...然后就可以写出转移状态方程了.注意如果dp[i]>dp[j] && i < j  则需要把dp[j]更新为dp[i]. #include<algorithm> #include<iostream> #include<cstring> #include<cstdio>…

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…

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…