Answers Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 25    Accepted Submission(s): 16 Problem Description   Sample Input 2 4 2 2 2 1 0 1 2 3   Sample Output NO YES YES YES   Source 2013 Mul…

Hyperspace Time Limit: 20000/10000 MS (Java/Others)    Memory Limit: 65535/65535 K (Java/Others)Total Submission(s): 67    Accepted Submission(s): 32 Problem Description The great Mr.Smith has invented a hyperspace particle generator. The device is v…

Palindrome subsequence Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/65535 K (Java/Others)Total Submission(s): 88    Accepted Submission(s): 26 Problem Description In mathematics, a subsequence is a sequence that can be derived from…

Palindrome subsequence Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/65535 K (Java/Others)Total Submission(s): 558    Accepted Submission(s): 203 Problem Description In mathematics, a subsequence is a sequence that can be derived fro…

Palindrome subsequence Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/65535 K (Java/Others) Total Submission(s): 2595    Accepted Submission(s): 1039 Problem Description In mathematics, a subsequence is a sequence that can be derived…

http://acm.hdu.edu.cn/showproblem.php?pid=4632 简单DP 代码: #include<iostream> #include<cstdio> #include<algorithm> #include<string> #include<cstring> #include<cmath> #include<set> #include<vector> #include<l…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4632 题目大意:给你若干个字符串,回答每个字符串有多少个回文子序列(可以不连续的子串).解题思路: 设dp[i][j]为[i,j]的回文子序列数,那么得到状态转移方程: dp[i][j]=(dp[i+1][j]+dp[i][j-1]-dp[i+1][j-1]+MOD)%MOD if(str[i]==str[j]) dp[i][j]+=dp[i-1][j+1]+1 代码: #include<cstdi…

题目链接 做的我很无奈,当时思路很乱,慌乱之中,起了一个想法,可以做,但是需要优化.尼玛,思路跑偏了,自己挖个坑,封榜之后,才从坑里出来,过的队那么多,开始的时候过的那么快,应该就不是用这种扯淡方法做的. 表示很无奈,没有想到简单的递推式,搞了一个MLE+TLE的方法. 最初版本,多了一个for的复杂度,只要标记一下就好,可是在递归了不好处理,让我折腾了老一会,才弄好. 复制代码 int dfs(int l,int r) { ; if(l == r) ; else if(l > r) ; if(…

题目 参考自博客:http://blog.csdn.net/u011498819/article/details/38356675 题意:查找这样的子回文字符串(未必连续,但是有从左向右的顺序)个数. 简单的区间dp,哎,以为很神奇的东西,其实也是dp,只是参数改为区间,没做过此类型的题,想不到用dp,以后就 知道了,若已经知道[0,i],推[0,i+1], 显然还要从i+1 处往回找,dp方程也简单: dp[j][i]=(dp[j+1][i]+dp[j][i-1]+10007-dp[j+1][…

题意 给定一个字符串,问有多少个回文子串(两个子串可以一样). 思路 注意到任意一个回文子序列收尾两个字符一定是相同的,于是可以区间dp,用dp[i][j]表示原字符串中[i,j]位置中出现的回文子序列的个数,有递推关系: dp[i][j]=dp[i+1][j]+dp[i][j-1]-dp[i+1][j-1]  (*) 如果i和j位置出现的字符相同,那么dp[i][j]可以由dp[i+1][j-1]中的子序列加上这两个字符构成回文子序列,也就是 dp[i][j]+=dp[i+1][j-1],注意…

题意1:问你一个串有几个不连续子序列(相同字母不同位置视为两个) 题意2:问你一个串有几种不连续子序列(相同字母不同位置视为一个,空串视为一个子序列) 思路1:由容斥可知当两个边界字母相同时 dp[i][j] = dp[i + 1][j] + dp[i][j - 1] - dp[i + 1][j - 1] + dp[i + 1][j - 1] + 1;当两个字母不同时 dp[i][j] = dp[i + 1][j] + dp[i][j - 1] - dp[i + 1][j - 1].然后区间DP…

GSM Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65535/32768 K (Java/Others)Total Submission(s): 622    Accepted Submission(s): 206 Problem Description Xiao Ming is traveling around several cities by train. And the time on the train is ver…

Arc of Dream Time Limit: 2000/2000 MS (Java/Others)    Memory Limit: 65535/65535 K (Java/Others)Total Submission(s): 0    Accepted Submission(s): 0 Problem Description An Arc of Dream is a curve defined by following function:wherea0 = A0ai = ai-1*AX+…

String Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65535/32768 K (Java/Others)Total Submission(s): 11    Accepted Submission(s): 4 Problem Description Given 3 strings A, B, C, find the longest string D which satisfy the following rules:a)…

Y Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 60    Accepted Submission(s): 20 Problem Description   Sample Input 4 1 2 1 3 1 4   Sample Output 1 Hint 1. The only set is {2,3,4}. 2. Please…

Sum Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 94    Accepted Submission(s): 41 Problem Description   Sample Input 2   Sample Output 2 Hint 1. For N = 2, S(1) = S(2) = 1. 2. The input fil…

Editor Time Limit: 3000/2000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 118    Accepted Submission(s): 38 Problem Description   Sample Input 8 I 2 I -1 I 1 Q 3 L D R Q 2   Sample Output 2 3 Hint The following…

EBCDIC Time Limit: 2000/2000 MS (Java/Others)    Memory Limit: 102400/102400 K (Java/Others)Total Submission(s): 160    Accepted Submission(s): 81 Problem Description A mad scientist found an ancient message from an obsolete IBN System/360 mainframe.…

Mine Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65535/32768 K (Java/Others)Total Submission(s): 51    Accepted Submission(s): 6 Problem Description Have you ever played a game in Windows: Mine?This game is played on a n*m board, just lik…

Palindrome subsequence Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/65535 K (Java/Others)Total Submission(s): 4513    Accepted Submission(s): 1935 Problem Description In mathematics, a subsequence is a sequence that can be derived f…

思路:设dp[i][j] 为i到j内回文子串的个数.先枚举所有字符串区间.再依据容斥原理. 那么状态转移方程为   dp[i][j] = dp[i][j-1] + dp[i+1][j] - dp[i+1][j-1] 如果 a[i] = a[j] , dp[i][j] += (dp[i+1][j-1] + 1). 或者 dp[i][j] =dp[i][j-1] + dp[i+1][j] 如果 a[i] != a[j] , dp[i][j] -=  dp[i+1][j-1]. 需要注意的是 假如区间…

Balls Rearrangement Time Limit: 9000/3000 MS (Java/Others)    Memory Limit: 65535/32768 K (Java/Others)Total Submission(s): 25    Accepted Submission(s): 8 Problem Description Bob has N balls and A boxes. He numbers the balls from 0 to N-1, and numbe…

Unshuffle Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 148    Accepted Submission(s): 43Special Judge Problem Description A shuffle of two strings is formed by interspersing the characters in…

Triangulation Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 96    Accepted Submission(s): 29 Problem Description There are n points in a plane, and they form a convex set. No, you are wrong. T…

MU Puzzle Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 134    Accepted Submission(s): 71 Problem Description Suppose there are the symbols M, I, and U which can be combined to produce strings…

Cut Pieces Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 131072/65536 K (Java/Others)Total Submission(s): 133    Accepted Submission(s): 62 Problem Description Suppose we have a sequence of n blocks. Then we paint the blocks. Each block sho…

Group Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 17    Accepted Submission(s): 5 Problem Description There are n men ,every man has an ID(1..n).their ID is unique. Whose ID is i and i-1 are…

Hehe Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 33    Accepted Submission(s): 22 Problem Description As we all know, Fat Brother likes MeiZi every much, he always find some topic to talk wi…

Fliping game Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 46    Accepted Submission(s): 35 Problem Description Alice and Bob are playing a kind of special game on an N*M board (N rows, M colu…

Palindrome subsequence Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 131072/65535 K (Java/Others) Total Submission(s): 2836 Accepted Submission(s): 1160 Problem Description In mathematics, a subsequence is a sequence that can be derived from a…