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裸的树状数组。敌兵布阵Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 26146 Accepted Submission(s): 11286Problem DescriptionC国的死对头A国这段时间正在进行军事演习，所以C国间谍头... 阅读全文
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StarsTime Limit: 1000MSMemory Limit: 65536KTotal Submissions: 25554Accepted: 11171DescriptionAstronomers often examine star maps where stars are represented by points on a plane and each star has Cart... 阅读全文
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树状数组是一个查询和修改复杂度都为log(n)的数据结构，假设数组a[1..n]，那么查询a[1]+…+a[n]的时间是log级别的，而且是一个在线的数据结构，支持随时修改某个元素的值，复杂度也为log级别。 图形表示Cn = A(n – 2^k + 1) + … + An ；此处的k为n的二进制形式末尾0的个数，可以利用Lowbit()函数找出k注意：下标不能从0开始：当i = 0，0 + L... 阅读全文
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Largest prime factorTime Limit: 5000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 5021 Accepted Submission(s): 1772Problem DescriptionEverybody knows any n... 阅读全文
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人生中的第一个并查集！！建树的时候虽然什么优化都没用。。。。 结果1S就过了Wireless NetworkTime Limit: 10000MSMemory Limit: 65536KTotal Submissions: 13429Accepted: 5687DescriptionAn earthquake takes place in Southeast Asia. The ACM (Asia... 阅读全文
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来自 http://blog.csdn.net/dm_vincent/article/details/7655764本文主要介绍解决动态连通性一类问题的一种算法，使用到了一种叫做并查集的数据结构，称为Union-Find。更多的信息可以参考Algorithms 一书的Section 1.5，实际上本文也就是基于它的一篇读后感吧。原文中更多的是给出一些结论，我尝试给出一些思路上的过程，即为什么要使用... 阅读全文
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人生中的第一个并查集！！建树的时候虽然什么优化都没用。。。。 结果1S就过了 Wireless NetworkTime Limit:10000MSMemory Limit:65536KTotal Submissions:13429Accepted:5687DescriptionAn earthquake takes place in Southeast Asia. The ACM (Asia Cooperated Medical team) have set up a wireless network with the lap computers,... 阅读全文
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盐水的故事Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 10284 Accepted Submission(s): 2457Problem Description挂盐水的时候，如果滴起来有规律，先是滴一滴，停一下；然后滴二滴，停一下... 阅读全文
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神奇的3分法，求单峰函数极值的利器！！！公式可以画图推导如下：x1=cos(a)*x+sin(a)*y;y1=cos(a)*y-sin(a)*x; Texas TripTime Limit:1000MSMemory Limit:65536KTotal Submissions:3429Accepted:1018DescriptionAfter a day trip with his friend Dick, Harry noticed a strange pattern of tiny holes in the door of his SUV. ... 阅读全文
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C. Main Sequencetime limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputAs you know, Vova has recently become a new shaman in the city of Ultima Thule. So... 阅读全文