hdu2489 Minimal Ratio Tree 题意:一个 至多  n=15 的 完全图 ,求 含有 m 个节点的树 使 边权和 除 点权和 最小 题解:枚举 m 个 点 ,然后 求 最小生成树 自己粗心....WA 了 好多次……(233333 ) #include <iostream> #include <cstring> #include <cstdio> #include <cmath> #include <algorithm> #…

Minimal Ratio Tree Time Limit : 2000/1000ms (Java/Other)   Memory Limit : 32768/32768K (Java/Other) Total Submission(s) : 12   Accepted Submission(s) : 7 Font: Times New Roman | Verdana | Georgia Font Size: ← → Problem Description For a tree, which n…

Minimal Ratio Tree Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) [Problem Description] For a tree, which nodes and edges are all weighted, the ratio of it is calculated according to the following equation.Given a…

Minimal Ratio Tree Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 2180    Accepted Submission(s): 630 Problem Description For a tree, which nodes and edges are all weighted, the ratio of it is…

Description For a tree, which nodes and edges are all weighted, the ratio of it is calculated according to the following equation. Given a complete graph of n nodes with all nodes and edges weighted, your task is to find a tree, which is a sub-graph…

Minimal Ratio Tree Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 2382    Accepted Submission(s): 709 Problem Description For a tree, which nodes and edges are all weighted, the ratio of it is…

Minimal Ratio Tree HDU - 2489 暴力枚举点,然后跑最小生成树得到这些点时的最小边权之和. 由于枚举的时候本来就是按照字典序的,不需要额外判. 错误原因:要求输出的结尾不能有空格. #include<cstdio> #include<cstring> #include<vector> using namespace std; ],ok2[]; ]; int num,n,m; ],b[][]; vector<int> vec; dou…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=2489 Problem Description For a tree, which nodes and edges are all weighted, the ratio of it is calculated according to the following equation. Given a complete graph of n nodes with all nodes and edges…

Minimal Ratio Tree Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 3345    Accepted Submission(s): 1019 Problem Description For a tree, which nodes and edges are all weighted, the ratio of it i…

想到枚举m个点,然后求最小生成树,ratio即为最小生成树的边权/总的点权.但是怎么枚举这m个点,实在不会.网上查了一下大牛们的解法,用dfs枚举,没想到dfs还有这么个作用. 参考链接:http://blog.csdn.net/xingyeyongheng/article/details/9373271 #include <stdio.h> #include <string.h> #include <set> #include <vector> #incl…

http://acm.hdu.edu.cn/showproblem.php?pid=2489 这道题就是n个点中选择m个点形成一个生成树使得生成树的ratio最小.暴力枚举+最小生成树. #include <cstdio> #include <cstring> #include <algorithm> #define maxn 1000 using namespace std; <<; ; int map[maxn][maxn]; int g[maxn][m…

题意:给定完全无向图,求其中m个子节点,要求Sum(edge)/Sum(node)最小. 思路:由于N很小,枚举所有可能的子节点可能情况,然后求MST,memset()在POJ G++里面需要cstring头文件. #include <iostream> #include <vector> #include <map> #include <cmath> #include <memory> #include <algorithm> #i…

hdu2489:http://acm.hdu.edu.cn/showproblem.php?pid=2489 题意:给你一个n个节点图,图的点有边权和点权,然后选取m个节点的子图,然后求这个一棵树,然后让这棵树的所有边权之和/所有点权之和的值最少. 题解:n很小,只有15,所以可以直接暴力,枚举每一种情况,然后求每一种情况的最小生成树,取最小的就可以了.但是这里的学到一个新的东西.就是判断a<b的时候,有可能a==b的时候由于浮点误差,也会被判成a<b,但是题目要的是字典序最小的,所以相等的时…

#include <stdio.h> #include <set> #include <string.h> #include <algorithm> using namespace std; ; ; double minans; int vis[maxn];//记录选中的点 int mp[maxn][maxn], ans[maxn][maxn]; int min_road[maxn]; int Prim(int n) { ; int dis[maxn]; i…

上图论课的时候无意之间看到了这个,然后花了几天的时间学习了下,接下来做一个总结. 一般斯坦纳树问题是指(来自百度百科): 斯坦纳树问题是组合优化问题,与最小生成树相似,是最短网络的一种.最小生成树是在给定的点集和边中寻求最短网络使所有点连通.而最小斯坦纳树允许在给定点外增加额外的点,使生成的最短网络开销最小. 然后听说已经被证明为是NP问题了,在ACM竞赛中我们不研究这个,我们研究更简单一些的问题. 对于图G(V,E),其中V表示图中点集,E表示图中边集.设A是V的某个子集,求至少包含A中所有点…

意甲冠军: 给你一幅这样子生成的图,求最小生成树的边权和. 思路:对于i >= 6的点连回去的5条边,打表知907^53 mod 2333333 = 1,所以x的循环节长度为54,所以9个点为一个循环,接下来的9个点连回去的边都是一样的. 预处理出5个点的全部连通状态.总共仅仅有52种,然后对于新添加一个点和前面点的连边状态能够处理出全部状态的转移. 然后转移矩阵能够处理出来了,高速幂一下就能够了,对于普通的矩阵乘法是sigma( a(i, k) * b(k, j) ) (1<=k<=N…

题意:有一个从根节点\(BFS\)得来的序列(每次\(bfs\)子节点的时候保证是升序放入队列的),现在让你还原树(没必要和之前相同),问能构造出的最小的树的深度. 题解:不看根节点,我们从第二个位置开始,如果某一段元素升序,那么就让他们变为上一层某个结点的儿子,否则,如果上一层还有另外的父节点的话,就作为它的子儿子,如果没有父亲结点可以连的话,就只能去下一层了,具体实现的话,我们可以统计每层结点的个数,如果下一层出现了降序的情况,就减去之前统计的个数,不断往复即可. 代码: int t; in…

转自:http://blog.csdn.net/shahdza/article/details/7779230 [HDU]1213 How Many Tables 基础并查集★1272 小希的迷宫 基础并查集★1325&&poj1308 Is It A Tree? 基础并查集★1856 More is better 基础并查集★1102 Constructing Roads 基础最小生成树★1232 畅通工程 基础并查集★2120 Ice_cream's world I 基础并查集★212…

http://vjudge.net/vjudge/contest/view.action?cid=54562#overview H  B. Polygons http://codeforces.com/problemset/problem/166/B 目前已知两种解法,先贴一个凸包的.算法是把两个多边形的点一起做一个凸包,看这个凸包是否包含b的点,包含说明b不是严格在a内,凸包要包括边上的点.复杂度nlogn,n为两个凸包点的和n=m+n=120000.nlogn=2024720. #inclu…

转自——http://blog.csdn.net/qwe20060514/article/details/8112550 =============================以下是最小生成树+并查集======================================[HDU]1213   How Many Tables   基础并查集★1272   小希的迷宫   基础并查集★1325&&poj1308  Is It A Tree?   基础并查集★1856   More i…

=============================以下是最小生成树+并查集====================================== [HDU] How Many Tables 基础并查集★ 小希的迷宫 基础并查集★ &&poj1308 Is It A Tree? 基础并查集★ More is better 基础并查集★ Constructing Roads 基础最小生成树★ 畅通工程 基础并查集★ 还是畅通工程 基础最小生成树★ 畅通工程 基础最小生成树★ 畅通…

Minimal Ratio Tree Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3899    Accepted Submission(s): 1196 Problem Description For a tree, which nodes and edges are all weighted, the ratio of it is…

=============================以下是最小生成树+并查集====================================== [HDU] 1213 How Many Tables 基础并查集★ 1272 小希的迷宫 基础并查集★ 1325&&poj1308 Is It A Tree? 基础并查集★ 1856 More is better 基础并查集★ 1102 Constructing Roads 基础最小生成树★ 1232 畅通工程 基础并查集★ 123…

=============================以下是最小生成树+并查集====================================== [HDU] 1213 How Many Tables 基础并查集★ 1272 小希的迷宫 基础并查集★ 1325&&poj1308 Is It A Tree? 基础并查集★ 1856 More is better 基础并查集★ 1102 Constructing Roads 基础最小生成树★ 1232 畅通工程 基础并查集★ 123…

Minimal Ratio TreeTime Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 4462    Accepted Submission(s): 1411 Problem Description For a tree, which nodes and edges are all weighted, the ratio of it is…

Given two sequences of letters A and B, find if B is a subsequence of A in thesense that one can delete some letters from A and obtain the sequence B. Greedy领先的思想.(always stay ahead) There is a line of 111 stalls, some of which need to be covered wit…

题目链接 http://vjudge.net/contest/137242#problem/D Description You're addicted to a little game called `remember the melody': you hear some notes, and then you repeat it. In most cases, the longer the melody, the harder to repeat, but it isn't always tr…

More important than algorithms(just problems #$!%), the techniques/concepts residing at the base of such algorithms is more important. There are broadly 4 ways in which classification of algorithms can be done. Classification by purpose Each algorith…

minimal spanning tree的经典题 /* ID: yingzho1 LANG: C++ TASK: agrinet */ #include <iostream> #include <fstream> #include <string> #include <map> #include <vector> #include <set> #include <algorithm> #include <stdio…

题目大意:有n个网站,由m条线路相连,每条线路都有一定的花费,找出连接所有线路的最小花费. 最小生成树问题(Minimal Spanning Tree, MST),使用Kruskal算法解决. #include <cstdio> #include <vector> #include <algorithm> using namespace std; typedef pair<int, int> ii; #define MAXN 1000100 int p[MA…