树的最小表示法 给定两个有根树的dfs序,问这两棵树是否同构 题解:http://blog.sina.com.cn/s/blog_a4c6b95201017tlz.html 题目要求判断两棵树是否是同构的,思路是用树的最小表示法去做.这里用的最小表示法就是将树的所有子树分别用1个字符串表示,要按字典序排序将他们依依连接起来.连接后如果两个字符串是一模一样的,那么他们必然是同构的.这样原问题就变成了子问题,子树又是一颗新的树. Source Code Problem: User: sdfzyhy…

Subway tree systems POJ - 1635 题目大意:给出两串含有‘1’和‘0’的字符串,0表示向下搜索,1表示回溯,这样深搜一颗树,深搜完之后问这两棵树是不是同一棵树 /* 在poj上交需要加一个string头文件,不然会CE 树的最小表示 这里用的最小表示法就是将树的所有子树分别用1个字符串表示,要按字典序排序将他们依依连接起来.连接后如果两个字符串是一模一样的,那么他们必然是同构的.这样原问题就变成了子问题,子树又是一颗新的树. */ #include<iostream>…

Description Some major cities have subway systems in the form of a tree, i.e. between any pair of stations, there is one and only one way of going by subway. Moreover, most of these cities have a unique central station. Imagine you are a tourist in o…

题意:给你两颗有根树,判定是否同构. 用了<Hash在信息学竞赛中的一类应用>中的哈希函数. len就是某结点的子树大小,g是某结点的孩子数+1. 这个值也是可以动态转移的!具体见论文,所以能高速处理出一颗无根树以每个顶点为根时的哈希值.改日敲个板子试试. #include<cstdio> #include<cstring> #include<vector> #include<algorithm> using namespace std; typ…

Word Puzzles Time Limit: 5000MS Memory Limit: 65536K Total Submissions: 10782 Accepted: 4076 Special Judge Description Word puzzles are usually simple and very entertaining for all ages. They are so entertaining that Pizza-Hut company started using t…

不可以理解的是,测评站上的0ms是怎么搞出来的. 这一题在建立超级源点和超级汇点后就变得温和可爱了.其实它本身就温和可爱.对比了能够找到的题解: (1)艾德蒙·卡普算法(2)迪尼克算法(3)改进版艾德蒙·卡普算法(MY METHOD) 不去管那个0ms的吧,那么(3)号算法最为美妙[它的别名是:ISAP],时间可观. 这个就算是一个ISAP的模板吧(除了输入的难看的几行外,其余均是标准的大米饼牌模板!) #include<stdio.h> #include<algorithm> #…

Time Limit: 3000MSMemory Limit: 65536K Total Submissions: 27109Accepted: 7527 Description David the Great has just become the king of a desert country. To win the respect of his people, he decided to build channels all over his country to bring water…

Time Limit: 1000MSMemory Limit: 65536K Total Submissions: 13849Accepted: 4851 Description In a certain course, you take n tests. If you get ai out of bi questions correct on test i, your cumulative average is defined to be . Given your test scores an…

Time Limit: 1000MSMemory Limit: 65536K Total Submissions: 19026Accepted: 8466 Description The Genographic Project is a research partnership between IBM and The National Geographic Society that is analyzing DNA from hundreds of thousands of contributo…

1.POJ1258 水水的prim……不过poj上硬是没过,wikioi上的原题却过了 #include<cstring> #include<algorithm> #include<cstdio> using namespace std; ,inf=1e8; ],g[maxn+][maxn+],ans=,n; ]; int main() { scanf("%d",&n); ;i<=n;++i) ;j<=n;++j) { scanf…