Dark roads Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1067    Accepted Submission(s): 474 Problem Description Economic times these days are tough, even in Byteland. To reduce the operating…

题目连接 http://acm.hdu.edu.cn/showproblem.php?pid=2988 Dark roads Description Economic times these days are tough, even in Byteland. To reduce the operating costs, the government of Byteland has decided to optimize the road lighting. Till now every road…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=2988 解题报告:一个裸的最小生成树,没看题,只知道结果是用所有道路的总长度减去最小生成树的长度和. #include<cstdio> #include<cstring> #include<iostream> #include<algorithm> using namespace std; ; ]; struct node { int front,rear,len…

最小生成树: 中文名 最小生成树 外文名 Minimum Spanning Tree,MST 一个有 n 个结点的连通图的生成树是原图的极小连通子图,且包含原图中的所有 n 个结点,并且有保持图连通的最少的边. 最小生成树可以用kruskal(克鲁斯卡尔)算法或prim(普里姆)算法求出. 最小生成树其实是最小权重生成树的简称.   应用: 生成树和最小生成树有许多重要的应用.   例如:要在n个城市之间铺设光缆,主要目标是要使这 n 个城市的任意两个之间都可以通信,但铺设光缆的费用很高,且各个…

Dark roads Time Limit : 2000/1000ms (Java/Other)   Memory Limit : 32768/32768K (Java/Other) Total Submission(s) : 7   Accepted Submission(s) : 2 Problem Description Economic times these days are tough, even in Byteland. To reduce the operating costs,…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1301 The Head Elder of the tropical island of Lagrishan has a problem. A burst of foreign aid money was spent on extra roads between villages some years ago. But the jungle overtakes roads relentlessly,…

最小生成树模板(嗯……在kuangbin模板里面抄的……) 最小生成树(prim) /** Prim求MST * 耗费矩阵cost[][],标号从0开始,0~n-1 * 返回最小生成树的权值,返回-1表示原图不连通 */ const int INF = 0x3f3f3f3f; const int MAXN = 110; bool vis[MAXN]; int lowc[MAXN]; int map[MAXN][MAXN]; int Prim(int cost[][MAXN], int n) {…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1102 Problem Description There are N villages, which are numbered from 1 to N, and you should build some roads such that every two villages can connect to each other. We say two village A and B are conne…

最小生成树. /* */ #include <iostream> #include <string> #include <map> #include <queue> #include <set> #include <stack> #include <vector> #include <deque> #include <algorithm> #include <cstdio> #inclu…

题目大意:输入一个整数n,表示村庄的数目.在接下来的n行中,每行有n列,表示村庄i到村庄 j 的距离.(下面会结合样例说明).接着,输入一个整数q,表示已经有q条路修好. 在接下来的q行中,会给出修好的路的起始村庄和结束村庄.. 输入样例说明如下: 解题思路:最小生成树(kruscal算法) 1)以前的题会直接给村庄编号以及村庄距离.而这道题,这是给出村庄的距离矩阵.村庄的编号信息蕴含在 矩阵中.这时候的读取方法为: for(i = 1 ; i <= n ; ++i){ for(j = i +…

题意是求将所有点联通所花费的最小金额,如不能完全联通,输出 -1 直接Kruskal,本题带来的一点教训是 rank 是algorithm头文件里的,直接做变量名会导致编译错误.没查到 rank 的具体用途...... #include <cstdio> #include <iostream> #include <algorithm> /*rank 是algorithm里的*/ using namespace std; ],r[]; int n,m,k,ans; str…

注意标号要减一才为下标,还有已建设的路长可置为0 题目 #define _CRT_SECURE_NO_WARNINGS #include <stdio.h> #include<string.h> #include <malloc.h> #include<stdlib.h> #include<algorithm> #include<iostream> using namespace std; #define M 110 #define…

Dark roads Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1031    Accepted Submission(s): 450 Problem Description Economic times these days are tough, even in Byteland. To reduce the operating…

题目:http://acm.hdu.edu.cn/showproblem.php?pid=1102 /************************************************************************/ /* hdu Constructing Roads 最小生成树 题目大意:在N个村子中已经存在部分存在连通,建最少长度的路使得所有的村子连通. 解题思路:已经连通的村子其中间的路径作为0,即修建的时候修建为0耗费,求这些节点的最小生成树. */ /*…

题目链接:HDU 1102 Constructing Roads Constructing Roads Problem Description There are N villages, which are numbered from 1 to N, and you should build some roads such that every two villages can connect to each other. We say two village A and B are conne…

Abandoned country Time Limit: 8000/4000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 4477    Accepted Submission(s): 1124 Problem Description An abandoned country has n(n≤100000) villages which are numbered from 1…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1102 题解: 纯最小生成树,只是有些边已经确定了要加入生成树中,特殊处理一下这些边就可以了. kruskal算法: 由于有些边已经确定,所以在调用kruskal()之前,就把这条边的两个顶点放在一个集合就可以了. #include<cstdio>//hdu1102 最小生成树 kruskal #include<algorithm> #define N 110 using namespa…

开学第三周.........真快尼 没有计划的生活真的会误入歧途anytime 表示不开心不开心不开心 每天都觉得自己的生活很忙 又觉得想做的事又没有完成 这学期本来计划重点好好学算法,打码码,臭臭美,做点兼职尼 坚持早起啊,一定一定!!!!坚持到成功为止!要不然之前努力就白费了 我想抽空看电影...学做PPt...口语...不能停.....6级.....觉得时间不过用尼  发现白天的生活就是死人一般啊...这些恼人的课ssssss和死板的teachersssssssss 抓 狂 我自我感爆棚了…

并查集:找祖先并更新,注意路径压缩,不然会时间复杂度巨大导致出错/超时 合并:(我的祖先是的你的祖先的父亲) 找父亲:(初始化祖先是自己的,自己就是祖先) 查询:(我们是不是同一祖先) 路径压缩:(每个点只保存祖先,不保存父亲) 最小生成树kruskal:贪心算法+并查集数据结构,根据边的多少决定时间复杂度,适合于稀疏图 核心思想贪心,找到最小权值的边,判断此边连接的两个顶点是否已连接,若没连接则连接,总权值+=此边权值,已连接就舍弃继续向下寻找: 并查集数据结构程序: #include<ios…

HDOJ(HDU).1025 Constructing Roads In JGShining's Kingdom (DP) 点我挑战题目 题目分析 题目大意就是给出两两配对的poor city和rich city,求解最多能修几条不相交的路.此题可以转化为LIS问题.转化过程如下: 数据中有2列,为方便表述,暂且叫做第一列和第二列. 1.若第一列是是递增的(给出的2个样例都是递增的),那么要想尽可能多的做连线,则那么就需要找出第二列中最长的递增子序列,若出现非递增的序列,那么连线后一定会相交.…

最小生成树——Kruskal与Prim算法 序: 首先: 啥是最小生成树??? 咳咳... 如图: 在一个有n个点的无向连通图中,选取n-1条边使得这个图变成一棵树.这就叫“生成树”.(如下图) 每个无向连通图都会拥有至少一个生成树. 而在无向连通图中,我们让每一个边都拥有一个边权(就是每个边代表一个值). 而我们在有边权的无向连通图中构造一个生成树,使得这个生成树所用的边的边权之和最小.这个生成树就叫这个无向连通图的最小生成树! 上图这个最小生成树的边权之和为9,是所有生成树中边权之和最小的.…

[转]最小生成树--Kruskal算法 标签(空格分隔): 算法 本文是转载,原文在最小生成树-Prim算法和Kruskal算法,因为复试的时候只用到Kruskal算法即可,故这里不再涉及Prim算法,如有需要可到原文查看. Kruskal算法 1.概览 Kruskal算法是一种用来寻找最小生成树的算法,由Joseph Kruskal在1956年发表.用来解决同样问题的还有Prim算法和Boruvka算法等.三种算法都是贪婪算法的应用.和Boruvka算法不同的地方是,Kruskal算法在图中存…

题目链接:hdu 5723 Abandoned country 题目大意:N个点,M条边:先构成一棵最小生成树,然后这个最小生成树上求任意两点之间的路径长度和,并求期望 /************************************************************** Problem:hdu 5723 User: youmi Language: C++ Result: Accepted Time:2932MS Memory:22396K solution:首先注意到任…

Jungle Roads 题目链接: http://acm.hust.edu.cn/vjudge/contest/124434#problem/A http://acm.hust.edu.cn/vjudge/contest/124434#problem/L Description The Head Elder of the tropical island of Lagrishan has a problem. A burst of foreign aid money was spent on e…

注意: 注意数组越界问题(提交出现runtimeError代表数组越界) 刚开始提交的时候,边集中边的数目和点集中点的数目用的同一个宏定义,但是宏定义是按照点的最大数定义的,所以提交的时候出现了数组越界问题,以后需要注意啦. Description The Head Elder of the tropical island of Lagrishan has a problem. A burst of foreign aid money was spent on extra roads betwe…

地址:http://acm.hdu.edu.cn/showproblem.php?pid=1301 很明显,这是一道“赤裸裸”的最小生成树的问题: 我这里采用了Kruskal算法,当然用Prim算法也一样可以解题. #include <iostream> #include <cstring> #include <cstdio> #include <cstdlib> using namespace std; typedef struct node{ int f…

Constructing Roads There are N villages, which are numbered from 1 to N, and you should build some roads such that every two villages can connect to each other. We say two village A and B are connected, if and only if there is a road between A and B,…

题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=1102 Constructing Roads Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 27178    Accepted Submission(s): 10340 Problem Description There are N vil…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1102 Constructing Roads Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 14172    Accepted Submission(s): 5402 Problem Description There are N villa…

The Head Elder of the tropical island of Lagrishan has a problem. A burst of foreign aid money was spent on extra roads between villages some years ago. But the jungle overtakes roads relentlessly, so the large road network is too expensive to mainta…