<?xml version="1.0" encoding="utf-8" ?><rss version="2.0"><channel><title><![CDATA[imfuture的专栏]]></title><description><![CDATA[]]></description><link>https://blog.youkuaiyun.com/imfuture</link><language>zh-cn</language><generator>https://blog.youkuaiyun.com/</generator><copyright><![CDATA[Copyright &copy; imfuture]]></copyright><item><title><![CDATA[HDU 5338 ZZX and Permutations]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/47399323</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/47399323</guid><author>imfuture</author><pubDate>Tue, 11 Aug 2015 10:40:32 +0800</pubDate><description><![CDATA[ZZX and Permutations
题解 线段树+set]]></description><category></category></item><item><title><![CDATA[欧拉函数+中国剩余定理]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/47129479</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/47129479</guid><author>imfuture</author><pubDate>Wed, 29 Jul 2015 17:54:53 +0800</pubDate><description><![CDATA[好久没写文章了。。
总结欧拉函数：
欧拉函数就是对于整数n，不超过n且与n互质的数的个数。
若mn为互质的正整数，那么f(mn)=f(m)*f(n);

因为任意正整数都可以唯一表示成如下形式:
                     k=p1^a1*p2^a2*……*pi^ai;(即分解质因数形式)
    可以推出:E(k)=(p1-1)(p2-1)……(pi-1)*(p1^(]]></description><category></category></item><item><title><![CDATA[c++ next_permutation()函数的使用]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/44925061</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/44925061</guid><author>imfuture</author><pubDate>Tue, 07 Apr 2015 20:02:21 +0800</pubDate><description><![CDATA[next_permutation（）函数在algorithm头文件里，参数为一个数组或字符串的头尾指针，返回值为bool型，调用后自动为数组排序。按照字典序从小到大，比如1234的next_permutation(a,a+4)就是1243.而4321的next_permutation()返回值即为false。
相应的，c++中还有一个prev_permutation()函数，跟next倒着。
]]></description><category></category></item><item><title><![CDATA[hdu 2795 （线段树）]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/44408101</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/44408101</guid><author>imfuture</author><pubDate>Wed, 18 Mar 2015 11:29:07 +0800</pubDate><description><![CDATA[原题在此


题意是在学校门前有一块宣传板，长w，高h，按照单位长度划分成h行。有n个长度分别为wi(1


这题用线段树的算法，我第一次没有想到，比较巧妙。把展板旋转九十度，从1到min(h,n)的一行，用每个变量来存下面每一行的长度w，构造线段树，节点上保存下面的长度的最大值。更新的时候就减去相应节点的wi，然后返回那个节点的L或者R，就是应该贴在的那一行。


代码：
#]]></description><category></category></item><item><title><![CDATA[hdoj 1509 Windows Message Queue 优先队列]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/44228409</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/44228409</guid><author>imfuture</author><pubDate>Thu, 12 Mar 2015 22:03:10 +0800</pubDate><description><![CDATA[Windows Message Queue
Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 4049    Accepted Submission(s): 1591



Problem Description

Mess]]></description><category></category></item><item><title><![CDATA[hdu 1010 Tempter of the Bone （dfs+剪枝）]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/41915311</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/41915311</guid><author>imfuture</author><pubDate>Sat, 13 Dec 2014 22:22:31 +0800</pubDate><description><![CDATA[题目传送门




简单的dfs和剪枝，卡了一天才过。

注意：是t时刻恰好到达door，不能提前也不能滞后。
还有一个小技巧叫做奇偶剪枝，如下：
从一个点a到另一个点b走的步数最少应该是abs(ax-bx)+abs(ay-by)；即上下和左右都向目标的方向走，每一步都更近，示意如下：




s
 
 
 
 


|
 
 
 
 


]]></description><category></category></item><item><title><![CDATA[zoj 3811 Untrusted Patrol 牡丹江网络赛c题]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/40514425</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/40514425</guid><author>imfuture</author><pubDate>Mon, 27 Oct 2014 20:33:42 +0800</pubDate><description><![CDATA[Untrusted Patrol

Time Limit: 3 Seconds      Memory Limit: 65536 KB

Edward is a rich man. He owns a large factory for health drink production. As a matter of course, there is a large warehouse in]]></description><category></category></item><item><title><![CDATA[简易计算器（栈的应用）]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/39853009</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/39853009</guid><author>imfuture</author><pubDate>Tue, 07 Oct 2014 12:07:07 +0800</pubDate><description><![CDATA[简单计算器
Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u
Submit Status Practice HDU
 1237




Description

读入一个只包含 +, -, *, / 的非负整数计算表达式，计算该表达式的值。 

 




In]]></description><category></category></item><item><title><![CDATA[zoj 1002 Fire Net (简单dfs)]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/39122615</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/39122615</guid><author>imfuture</author><pubDate>Sun, 07 Sep 2014 21:22:58 +0800</pubDate><description><![CDATA[Fire Net

Time Limit: 2 Seconds      Memory Limit: 65536 KB

Suppose that we have a square city with straight streets. A map of a city is a square board with n rows and n columns, each representin]]></description><category></category></item><item><title><![CDATA[poj 1166 敌兵布阵 线段树]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/38541473</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/38541473</guid><author>imfuture</author><pubDate>Wed, 13 Aug 2014 19:59:47 +0800</pubDate><description><![CDATA[敌兵布阵
Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 44035    Accepted Submission(s): 18715



Problem Description

C国的死对头A国这段时间正在进行军事演]]></description><category></category></item><item><title><![CDATA[hdu 2571 fate 动态规划水题]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/38390305</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/38390305</guid><author>imfuture</author><pubDate>Tue, 05 Aug 2014 20:34:22 +0800</pubDate><description><![CDATA[Fate
Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d
 & %I64u
Submit Status




Description

穿过幽谷意味着离大魔王lemon已经无限接近了！
可谁能想到，yifenfei在斩杀了一些虾兵蟹将后，却再次面临命运大迷宫的考验，这是魔王lemon设]]></description><category></category></item><item><title><![CDATA[hdu 1227 fast food 动态规划]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/38382737</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/38382737</guid><author>imfuture</author><pubDate>Tue, 05 Aug 2014 11:16:16 +0800</pubDate><description><![CDATA[Fast Food
Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d
 & %I64u
Submit Status Practice HDU
 1227




Description

The fastfood chain McBurger owns several restaurant]]></description><category></category></item><item><title><![CDATA[hit oj 1760 The jackpot （最大子段和）]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/38381101</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/38381101</guid><author>imfuture</author><pubDate>Tue, 05 Aug 2014 10:38:59 +0800</pubDate><description><![CDATA[As Manuel wants to get rich fast and without too much work, he decided to make a career in gambling. Initially, he plans to study the gains and losses of players, so that, he can identify patterns of ]]></description><category></category></item><item><title><![CDATA[HDU 2046+HDU1143（递推）覆盖问题]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/38322613</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/38322613</guid><author>imfuture</author><pubDate>Thu, 31 Jul 2014 19:54:31 +0800</pubDate><description><![CDATA[骨牌铺方格
Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 28534    Accepted Submission(s): 13842



Problem Description

在2×n的一个长方形方格中,用一个1]]></description><category></category></item><item><title><![CDATA[poj1753 FlipGame]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/38048349</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/38048349</guid><author>imfuture</author><pubDate>Tue, 22 Jul 2014 19:59:47 +0800</pubDate><description><![CDATA[Flip Game




Time Limit: 1000MS
 
Memory Limit: 65536K


Total Submissions: 30172
 
Accepted: 13094




Description

Flip game is played on a rectangular 4x4 field with two-sided p]]></description><category></category></item><item><title><![CDATA[快速幂模]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/38034637</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/38034637</guid><author>imfuture</author><pubDate>Tue, 22 Jul 2014 09:57:09 +0800</pubDate><description><![CDATA[a^b mod c  0



/**//****************************************************/
//                   模取幂运算 计算a^b mod c
//                  利用公式   
//                  (a*b)mod(c) = ((a mod c )*b)mod c ]]></description><category></category></item><item><title><![CDATA[hdu 1232 畅通工程  并查集]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/26140025</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/26140025</guid><author>imfuture</author><pubDate>Sun, 18 May 2014 11:55:17 +0800</pubDate><description><![CDATA[畅通工程
Time Limit:2000MS     Memory Limit:32768KB     64bit IO Format:%I64d
 & %I64u
Submit Status




Description

某省调查城镇交通状况，得到现有城镇道路统计表，表中列出了每条道路直接连通的城镇。省政府“畅通工程”的目标是使全省任何两个城镇间都可以实现交通（但不一定有]]></description><category></category></item><item><title><![CDATA[poj 3253 Fence repair]]></title><link>https://blog.youkuaiyun.com/imfuture/article/details/26096793</link><guid>https://blog.youkuaiyun.com/imfuture/article/details/26096793</guid><author>imfuture</author><pubDate>Sat, 17 May 2014 21:29:45 +0800</pubDate><description><![CDATA[Fence Repair




Time Limit: 2000MS
 
Memory Limit: 65536K


Total Submissions: 24144
 
Accepted: 7698




Description

Farmer John wants to repair a small length of the fence aroun]]></description><category></category></item></channel></rss>