Binary codes Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 5647   Accepted: 2201 Description Consider a binary string (b1-bN) with N binary digits. Given such a string, the matrix of Figure 1 is formed from the rotated versions of the…

Binary Witch http://poj.org/problem?id=2541 Time Limit: 1000MS   Memory Limit: 65536K       Description Once upon a time in the silent depths of digital forests there lived a Binary Witch. She was able to forecast weather, telling for any day in the…

相应POJ 题目:点击打开链接 Binary Search Heap Construction Time Limit: 2000MS   Memory Limit: 30000K Total Submissions: 9075   Accepted: 2566 Description Read the statement of problem G for the definitions concerning trees. In the following we define the basic…

Binary Stirling Numbers Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 1761   Accepted: 671 Description The Stirling number of the second kind S(n, m) stands for the number of ways to partition a set of n things into m nonempty subsets.…

题目链接:http://poj.org/problem?id=2499 思路分析:结点向左边移动时结点(a, b)变为( a+b, b),向右边移动时( a, b )变为( a, a + b); 为求最短路径<a1, a2, a3,...,an>, 考虑从已经知道的结点(a, b)开始找出最短路径回到根节点(1, 1),即向左移动次数和向右移动次数最少回到根节点,由贪心算法, 若 a>b 时,a 减少最大即减去 b,若 a < b,b 减少最大即减去a值,循环直到到达根节点(1,…

ID Codes Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 6229   Accepted: 3737 Description It is 2084 and the year of Big Brother has finally arrived, albeit a century late. In order to exercise greater control over its citizens and ther…

ID Codes Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 7644   Accepted: 4509 Description It is 2084 and the year of Big Brother has finally arrived, albeit a century late. In order to exercise greater control over its citizens and ther…

题目链接 http://poj.org/problem?id=1430 题解 qaq写了道水题-- 在模\(2\)意义下重写一下第二类Stirling数的递推式: \[S(n,m)=S(n-1,m-1)+(S(n-1,m)\ \text{and}\ m)\] 令\(S'(n,m)=S(n+m,m)\), 那么递推式变成了\(S'(n,m)=S'(n,m-1)+(S'(n-1,m)\ \text{and}\ m)\) 也就相当于从\((0,0)\)走到\((n,m)\)的NE Lattice Pa…

逆序KMP,真的是强大! 参考链接,下面有题意解释:http://blog.sina.com.cn/s/blog_6ec5c2d00100tphp.htmlhttp://blog.csdn.net/sdjzping/article/details/8857749http://tech.ddvip.com/2013-09/1380477442203505.html 直接暴力是枚举字符串的后面13个的字母,然后再用KMP匹配,这样的话,就绪要枚举多次,分别是后面的13,12,11....1个字母.但…

题意:二叉树的根节点为(1,1),对每个结点(a,b)其左结点为 (a + b, b) ,其右结点为 (a, a + b),已知某结点坐标,求根节点到该节点向左和向右走的次数. 分析:往回一步一步走肯定超时,不过如果a>b,大的有点多,就没必要一步一步走,直接a/b就好了,然后把a变成a%b取余,那么a/b就是从现在的a到原来的a向左走的步数.(a<b同理) 同理,如果a=1的话,那么也没必要往回走了,因为从根节点到现在的结点就是向右走了b-1.(b=1同理) #pragma comment(…