最小生成树，继续水~

来源：互联网发布：泡妞宝鉴天地知我心txt 编辑：程序博客网时间：2024/05/17 04:42

题目链接：http://openoj.awaysoft.com:8080/judge/contest/contest/view.action?cid=384#problem/I

#include <stdio.h>#include <string.h>#include <math.h>#include <stdlib.h>double dis[510][510];int vist[510];struct node {    int x,y;}p[510];double map(node a,node b){    return ( sqrt( (a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y) ) );}int cmp(void const *a,void const *b){    return (*(double *)a)<(*(double *)b);}int main(){    int t,n,m,i,j;    double a[510];    scanf("%d",&t);    while (t--)    {        double s=0;        scanf("%d%d",&m,&n);        for (i=1;i<=n;i++)            scanf("%d%d",&p[i].x,&p[i].y);        for (i=1;i<n;i++)            for (j=i+1;j<=n;j++)                dis[i][j]=dis[j][i]=map(p[i],p[j]);         /*for (i=1;i<=n;i++)        {            for (j=1;j<=n;j++)                printf("%lf ",dis[i][j]);                printf("\n");        }*/        memset(vist,0,sizeof(vist));        vist[1]=1;        int T=n-1;        int num=0;        while (T--)        {            int pos;            double m=10010;            for (i=2;i<=n;i++)                if (!vist[i] && dis[1][i]<m)                {                    pos=i;                    m=dis[1][i];                }            vist[pos]=1;            a[num++]=m;            for (i=2;i<=n;i++)                if (!vist[i]&& dis[pos][i]<dis[1][i])                    dis[1][i]=dis[pos][i];        }        qsort(a,num,sizeof(a[0]),cmp);        printf("%0.2lf\n",a[m-1]);    }    return 0;    }