DP。听了同学的讲解才会的。 具体做法:dp[i][j]表示长度为 i 的括号串,前缀和(左括号表示1,右括号表示-1)为 j 的有几种。 状态转移很容易得到:dp[i][j]=dp[i - 1][j + 1]+dp[i - 1][j - 1],表示 i 这位分别放上右括号和左括号。 然后就是要处理
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其他好文 时间:
2016-02-23 11:11:56
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162
只有一周了QAQ 2.21 CF 629 E Famil Door and Roads 其实Tarjan的时候搞一搞,就O(n+m)了吖。 1 #include <iostream> 2 #include <cstdio> 3 #include <vector> 4 using namespace
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其他好文 时间:
2016-02-21 18:35:16
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127
Problem Description Everyone knows Matt enjoys playing games very much. Now, he is playing such a game. There are N rooms, each with one door. There a
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其他好文 时间:
2016-02-11 13:24:36
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239
链接:http://poj.org/problem?id=1300 题意:有n个房间。每一个房间有若干个门和别的房间相连。管家从m房间開始走。要回到自己的住处(0),问是否有一条路能够走遍全部的门而且没有反复的路。 无向图欧拉通路充要条件:G为连通图,而且G仅有两个奇度结点(度数为奇数的顶点)或者无
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其他好文 时间:
2016-02-02 22:24:08
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186
瘦蛟舞·2015/11/02 10:50作者:瘦蛟舞,蒸米”You can’t have a back door in the software because you can’t have a back door that’s only for the good guys.“ - Apple CE...
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移动开发 时间:
2015-12-29 16:08:50
阅读次数:
343
首先,先在中加入门 然后写好大门的css,如下:[由于本人设计不好,所以这里的门都是用颜色块代替的,大家在用的时候可以换成各种门的背景] div{ margin:0; padding:0; } .door{ width:450px; height:450px; position:r...
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Web程序 时间:
2015-11-23 01:01:48
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235
DescriptionAfter a day trip with his friend Dick, Harry noticed a strange pattern of tiny holes in the door of his SUV. The local American Tire store ...
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其他好文 时间:
2015-09-24 12:37:33
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168
问题重述:There are 100 doors in a long hallway. They are all closed. The first time you walk by each door, you open it. The second time around, you close ...
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其他好文 时间:
2015-09-09 11:20:31
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159
Problem DescriptionEveryone knows Matt enjoys playing games very much. Now, he is playing such a game. There are N rooms, each with one door. There ar...
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其他好文 时间:
2015-09-07 22:31:52
阅读次数:
301
As your coach and friend, I can assure you the door toall the best things in the world will open to you but the key to that door isin your hand. You must do your part, you must faithfully follow the plans youmake and take the actions you plan. You must nev...
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其他好文 时间:
2015-08-31 23:47:03
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298