hdu 1863 畅通工程

来源：互联网发布：中国软件外包印度差距编辑：程序博客网时间：2024/06/05 22:52
#include <stdio.h>#include <string.h>#include <iostream>#include <algorithm>#include <vector>#include <queue>#include <set>#include <map>#include <string>#include <math.h>#include <stdlib.h>#include <time.h>using namespace std;struct data{    int u,v;    double w;}e[5000];bool cmp(data a, data b){    return a.w<b.w;}double x[100+5],y[100+5];int n,m,bin[5000];int Find(int x){    int s;    for(s=x;bin[s]>=0;s=bin[s]);    while(s!=x)    {        int t=bin[x];        bin[x]=s;        x=t;    }    return s;}void Union(int x1,int x2){    int f1=Find(x1),f2=Find(x2);    int t=bin[f1]+bin[f2];    if(bin[f1]>bin[f2])    {        bin[f1]=f2;        bin[f2]=t;    }    else    {        bin[f2]=f1;        bin[f1]=t;    }}int main(){    int i,j,cas=0,num,u,v;    double t,sum;    while(~scanf("%d%d",&n,&m))    {        if(n==0) break;        for(i=0;i<=m;i++)            bin[i]=-1;        for(i=0;i<n;i++)            {                scanf("%d%d%d",&e[i].u,&e[i].v,&e[i].w);            }        sort(e,e+n,cmp);        sum=0;        num=0;        for(i=0;i<n;i++)        {            u=e[i].u;            v=e[i].v;            if(Find(u)!=Find(v))            {                sum+=e[i].w;                Union(u,v);                num++;            }            if(num>=m-1) break;        }        if(num>=m-1) printf("%d\n",sum);        else printf("?\n");    }    return 0;}
0 0