zoukankan      html  css  js  c++  java
  • Dark roads--hdoj

                                                  Dark roads

    Time Limit : 2000/1000ms (Java/Other)   Memory Limit : 32768/32768K (Java/Other)
    Total Submission(s) : 4   Accepted Submission(s) : 1
    Problem 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 was illuminated all night long, which costs 1 Bytelandian Dollar per meter and day. To save money, they decided to no longer illuminate every road, but to switch off the road lighting of some streets. To make sure that the inhabitants of Byteland still feel safe, they want to optimize the lighting in such a way, that after darkening some streets at night, there will still be at least one illuminated path from every junction in Byteland to every other junction.

    What is the maximum daily amount of money the government of Byteland can save, without making their inhabitants feel unsafe?

     

    Input
    The input file contains several test cases. Each test case starts with two numbers m and n, the number of junctions in Byteland and the number of roads in Byteland, respectively. Input is terminated by m=n=0. Otherwise, 1 ≤ m ≤ 200000 and m-1 ≤ n ≤ 200000. Then follow n integer triples x, y, z specifying that there will be a bidirectional road between x and y with length z meters (0 ≤ x, y < m and x ≠ y). The graph specified by each test case is connected. The total length of all roads in each test case is less than 2[sup]31[/sup].
     

    Output
    For each test case print one line containing the maximum daily amount the government can save.
     

    Sample Input
    7 11 0 1 7 0 3 5 1 2 8 1 3 9 1 4 7 2 4 5 3 4 15 3 5 6 4 5 8 4 6 9 5 6 11 0 0
     

    Sample Output
    51
     

    Source
    2009/2010 Ulm Local Contest
     


    #include<stdio.h>
    #include<string.h>
    #include<stdlib.h>
    #include<algorithm>
    using namespace std;
    int pre[200010],n,m;
    struct s
    {
    	int x,y,v;
    }b[200010];
    int cmp(s n1,s n2)
    {
    	return n1.v<n2.v;
    }
    int find(int a)
    {
    	int r=a,i,j;
    	while(r!=pre[r])
    		r=pre[r];
    	i=a;
    	while(i!=r)
    	{
    		j=pre[i];
    		pre[i]=r;
    		i=j;
    	}
    	return r;
    }
    int fun()
    {
    	int sum=0,i,j,k;
    	for(i=0;i<m;i++)
    	{
    		int fa,fb;
    		fa=find(b[i].x);
    		fb=find(b[i].y);
    		if(fa!=fb)
    		{
    			pre[fa]=fb;
    			sum+=b[i].v;
    		}
    	}
    	return sum;
    }
    int main()
    {
    	//int n,m;
    	while(scanf("%d%d",&n,&m)!=EOF,n||m)
    	{
    		int i,sum=0,ans;
    		for(i=0;i<=n;i++)
    			pre[i]=i;
    		for(i=0;i<m;i++)
    		{
    			scanf("%d%d%d",&b[i].x,&b[i].y,&b[i].v);
    			sum+=b[i].v;
    		}
    		sort(b,b+m,cmp);
    		ans=fun();
    		printf("%d
    ",sum-ans);
    	}
    }



  • 相关阅读:
    Linux_修改网卡名
    综合架构_ansible_剧本编写
    综合架构_ansible自动化管理服务
    Linux_综合架构_ssh基于密钥_远程连接
    NFS项目实践
    综合架构_实时同步服务 inotify
    综合架构_nfs常见错误
    linux_知识点集锦
    企业全网备份数据
    综合架构_存储服务nfs
  • 原文地址:https://www.cnblogs.com/playboy307/p/5273840.html
Copyright © 2011-2022 走看看