hdu 2122（Ice_cream’s world III）（最小生成树，两种算法都可以）

Ice_cream’s world III

Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)

Total Submission(s): 926    Accepted Submission(s): 303

Problem Description

ice_cream’s world becomes stronger and stronger; every road is built as undirected. The queen enjoys traveling around her world; the queen’s requirement is like II problem, beautifies the roads, by which there are some ways from every city to the capital. The project’s cost should be as less as better.

 

Input

Every case have two integers N and M (N<=1000, M<=10000) meaning N cities and M roads, the cities numbered 0…N-1, following N lines, each line contain three integers S, T and C, meaning S connected with T have a road will cost C.

 

Output

If Wiskey can’t satisfy the queen’s requirement, you must be output “impossible”, otherwise, print the minimum cost in this project. After every case print one blank.

 

Sample Input

2 1 0 1 10 4 0

 

Sample Output

10 impossible

 

Author

Wiskey

 

Source

HDU 2007-10 Programming Contest_WarmUp

最小生成树：prime 算法，还有克鲁斯卡尔算法。

两者都可以处理。

prime代码如下：

#include
#include
int v[10010],map[10010][10010];
#define inf 0xfffffff;
int main()
{
	int n,m,i,j,a,b,c;
	while(~scanf("%d%d",&n,&m))
	{
		int sum=0;
		memset(v,0,sizeof(v));
		for(i=0;imap[flag][j])
				map[0][j]=map[flag][j];
			}
		}
		if(flag==-1)
		printf("impossible\n\n");
		else
		printf("%d\n\n",sum);
	}
	return 0;
}

kuskal算法代码如：

#include
#include
using namespace std;
struct node{
	int a,b,c;
}s[10010];
int father[10010];
int find(int r)
{
	return r==father[r]?r:find(father[r]);
}
int cmp(node x,node y)
{
	return x.c