Shawn_Ji

2016年7月13日

摘要：原题： Description Recently, Pari and Arya did some research about NP-Hard problems and they found the minimum vertex coverproblem very interesting. Supp 阅读全文

posted @ 2016-07-13 21:41 Shawn_Ji 阅读(282) 评论(1) 推荐(1) 编辑

codeforces 361 D - Friends and Subsequences

摘要：原题： Description Mike and !Mike are old childhood rivals, they are opposite in everything they do, except programming. Today they have a problem they c 阅读全文

posted @ 2016-07-13 10:56 Shawn_Ji 阅读(298) 评论(0) 推荐(0) 编辑

codeforces 361 E - Mike and Geometry Problem

摘要：原题： Description Mike wants to prepare for IMO but he doesn't know geometry, so his teacher gave him an interesting geometry problem. Let's define f([l 阅读全文

posted @ 2016-07-13 10:45 Shawn_Ji 阅读(151) 评论(0) 推荐(0) 编辑

2016年7月12日

线段树算法学习

摘要： http://www.cnblogs.com/TenosDoIt/p/3453089.html#b 线段树的思想是将一整个区间二分拆成多个不重合的2段区间，知道不能拆分为止。例如对于数组[2, 5, 1, 4, 9, 3]可以构造如下的二叉树（背景为白色表示叶子节点，非叶子节点的值是其对应数组区阅读全文

posted @ 2016-07-12 20:44 Shawn_Ji 阅读(1256) 评论(0) 推荐(0) 编辑

RMQ（范围最值问题）算法学习

摘要： RMQ算法适合求解对一个数组多次查询给定范围内的最值。预处理操作：令d[i,j]表示从i开始，长度为2^j的一段元素的最值，可以用递推公式写出d[i,j] = min{ d[i][j-1], d[ i+2^(j-1) ][j-1] } 原理如图所示：复杂度：因为2^j<=n，所以d数组的元素阅读全文

posted @ 2016-07-12 19:13 Shawn_Ji 阅读(255) 评论(0) 推荐(0) 编辑

2016年7月11日

codeforces 361 A - Mike and Cellphone

摘要：原题： Description While swimming at the beach, Mike has accidentally dropped his cellphone into the water. There was no worry as he bought a cheap repla 阅读全文

posted @ 2016-07-11 21:06 Shawn_Ji 阅读(159) 评论(0) 推荐(0) 编辑

codeforces 361 B - Mike and Shortcuts

摘要：原题： Description Recently, Mike was very busy with studying for exams and contests. Now he is going to chill a bit by doing some sight seeing in the ci 阅读全文

posted @ 2016-07-11 20:28 Shawn_Ji 阅读(257) 评论(0) 推荐(0) 编辑

CodeForces 689C Mike and Chocolate Thieves （二分）

摘要：原题：原题： Description Bad news came to Mike's village, some thieves stole a bunch of chocolates from the local factory! Horrible! Aside from loving swee 阅读全文

posted @ 2016-07-11 20:09 Shawn_Ji 阅读(213) 评论(0) 推荐(0) 编辑

2016年5月29日

随笔—邀请赛前训— Codeforces Round #330 (Div. 2) B题

摘要：题意：这道英文题的题意稍稍有点复杂。找长度为n的数字序列有多少种。这个序列可以分为n/k段，每段k个数字。k个数可以变成一个十进制的数Xi。要求对这每n/k个数，剔除Xi可被ai整除的情况，剔除X的第一个数（包括前导0）是bi的情况。问剩下的组合有多少种。思路：这题我是一波三折的。首先也没有阅读全文

posted @ 2016-05-29 15:42 Shawn_Ji 阅读(165) 评论(0) 推荐(0) 编辑

随笔—邀请赛前训— Codeforces Round #330 (Div. 2) Vitaly and Night

摘要：题意：给你很多对数，要么是0要么是1。不全0则ans++。思路即题意。阅读全文

posted @ 2016-05-29 15:14 Shawn_Ji 阅读(111) 评论(0) 推荐(0) 编辑

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