POJ 1751 Highways （ZOJ 2048 ） MST

http://poj.org/problem?id=1751

http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=2048

题目大意：

给你n个点的坐标，并且m个点之间已经建立起连接，让你输出剩下的MST的连接点。

两题其实一样。就输入一点点不同。

因为题目采用Special Judge故水题一题。

POJ:

#include<cstdio>
#include<cmath>
#include<algorithm>
using namespace std;
const int MAXN=755;
const int INF=9999999;
int fa[MAXN];

struct point
{
	double x,y;
}ship[MAXN];

struct dot
{
	int x,y;
	double dis;
}dis[MAXN*MAXN];

int find(int cur)
{
	return fa[cur]==cur?cur:fa[cur]=find(fa[cur]);
}

bool operator < (const dot &a,const dot& b)
{
	return a.dis<b.dis;
}

int main()
{
	int n,kase=1;

	while(~scanf("%d",&n))
	{
		if(kase!=1)
			printf("\n");
		kase++;

		int i,j;
		for(i=1;i<=n;i++)
			scanf("%lf%lf",&ship[i].x,&ship[i].y);

		int len=0;
		for(i=1;i<=n;i++)
		{
			for(j=i+1;j<=n;j++)
			{
				dis[len].x=i;
				dis[len].y=j;
				dis[len].dis=sqrt((ship[j].y -ship[i].y) *(ship[j].y -ship[i].y) + (ship[j].x -ship[i].x)*(ship[j].x -ship[i].x));

				len++;
			}
		}

		for(i=1;i<=n;i++)
			fa[i]=i;

		int m;
		scanf("%d",&m);
		for(i=1;i<=m;i++)
		{
			int x,y;
			scanf("%d%d",&x,&y);
			int rootx=find(x);
			int rooty=find(y);
			fa[rootx]=rooty;
		}
		sort(dis,dis+len);

		for(i=0;i<len;i++)
		{
			int rootx=find(dis[i].x);
			int rooty=find(dis[i].y);
			if(rootx!=rooty)
			{
				printf("%d %d\n",dis[i].x,dis[i].y);
				fa[rootx]=rooty;
			}
		}

	}
	return 0;
}

ZOJ：

#include<cstdio>
#include<cmath>
#include<algorithm>
using namespace std;
const int MAXN=755;
const int INF=9999999;
int fa[MAXN];

struct point
{
	double x,y;
}ship[MAXN];

struct dot
{
	int x,y;
	double dis;
}dis[MAXN*MAXN];

int find(int cur)
{
	return fa[cur]==cur?cur:fa[cur]=find(fa[cur]);
}

bool operator < (const dot &a,const dot& b)
{
	return a.dis<b.dis;
}

int main()
{
	int T,n,kase=1;
	scanf("%d",&T);

	while(T--)
	{
		if(kase!=1)
			printf("\n");
		kase++;
		scanf("%d",&n);

		int i,j;
		for(i=1;i<=n;i++)
			scanf("%lf%lf",&ship[i].x,&ship[i].y);

		int len=0;
		for(i=1;i<=n;i++)
		{
			for(j=i+1;j<=n;j++)
			{
				dis[len].x=i;
				dis[len].y=j;
				dis[len].dis=sqrt((ship[j].y -ship[i].y) *(ship[j].y -ship[i].y) + (ship[j].x -ship[i].x)*(ship[j].x -ship[i].x));

				len++;
			}
		}

		for(i=1;i<=n;i++)
			fa[i]=i;

		int m;
		scanf("%d",&m);
		for(i=1;i<=m;i++)
		{
			int x,y;
			scanf("%d%d",&x,&y);
			int rootx=find(x);
			int rooty=find(y);
			fa[rootx]=rooty;
		}
		sort(dis,dis+len);

		for(i=0;i<len;i++)
		{
			int rootx=find(dis[i].x);
			int rooty=find(dis[i].y);
			if(rootx!=rooty)
			{
				printf("%d %d\n",dis[i].x,dis[i].y);
				fa[rootx]=rooty;
			}
		}

	}
	return 0;
}