hdu2489之最小生成树

Minimal Ratio Tree

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 1733    Accepted Submission(s): 505


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 weighted, your task is to find a tree, which is a sub-graph of the original graph, with m nodes and whose ratio is the smallest among all the trees of m nodes in the graph.
 

Input
Input contains multiple test cases. The first line of each test case contains two integers n (2<=n<=15) and m (2<=m<=n), which stands for the number of nodes in the graph and the number of nodes in the minimal ratio tree. Two zeros end the input. The next line contains n numbers which stand for the weight of each node. The following n lines contain a diagonally symmetrical n×n connectivity matrix with each element shows the weight of the edge connecting one node with another. Of course, the diagonal will be all 0, since there is no edge connecting a node with itself.



All the weights of both nodes and edges (except for the ones on the diagonal of the matrix) are integers and in the range of [1, 100].

The figure below illustrates the first test case in sample input. Node 1 and Node 3 form the minimal ratio tree. 
hdu2489之最小生成树_第1张图片

 

Output
For each test case output one line contains a sequence of the m nodes which constructs the minimal ratio tree. Nodes should be arranged in ascending order. If there are several such sequences, pick the one which has the smallest node number; if there's a tie, look at the second smallest node number, etc. Please note that the nodes are numbered from 1 .
 

Sample Input
 
   
3 2 30 20 10 0 6 2 6 0 3 2 3 0 2 2 1 1 0 2 2 0 0 0
 

Sample Output
 
   
1 3 1 2
题意:输入n个点,要求选m个点满足连接m个点的m-1条边权值和sum与点的权值和ans最小,即sum/ans最小,并输出所选的m个点,如果有多种情况就选第一个点最小的,如果第一个点也相同就选第二个点最小的........


分析:因为n<=15,所以可以暴力枚举出所选的m个点,然后对这m个点进行最小生成树求得m-1条边的最小和,然后求sum/ans即可

//http://acm.hdu.edu.cn/showproblem.php?pid=2489
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define INF 99999999
using namespace std;

const int MAX=15+5;
int edge[MAX][MAX],dist[MAX],node[MAX];//node记录最终选的点 
int vale[MAX],temp[MAX],n,m;//temp记录选的m个点
double minratio;
bool mark[MAX];

int Prim(int s){
	int sum=0;
	for(int i=1;i<=m;++i)mark[temp[i]]=false,dist[temp[i]]=edge[s][temp[i]];
	mark[s]=true;
	dist[s]=0;
	for(int i=1;idist[temp[j]])point=temp[j];
		}
		mark[point]=true;
		sum+=dist[point];
		for(int j=1;j<=m;++j){
			if(!mark[temp[j]] && edge[point][temp[j]]>n>>m,n+m){
		minratio=INF*1.0;
		for(int i=1;i<=n;++i)cin>>vale[i];
		for(int i=1;i<=n;++i){
			for(int j=1;j<=n;++j){
				cin>>edge[i][j];
			}
		}
		for(int i=1;i<=n;++i){
			temp[1]=i;
			dfs(i,1);
		}
		for(int i=1;i



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