POJ 2236并查集

来源：互联网发布：心灵鸡汤知乎编辑：程序博客网时间：2024/05/22 12:49
#include"stdio.h"#include"iostream"#include"map"#include"set"using namespace std;const int maxn=1050;double d;int pre[maxn];struct point{double x,y;}a[maxn];void init(int n){    for(int i=1;i<=n;i++)        pre[i]=i;}int Find(int x){    return pre[x]==x?x:pre[x]=Find(pre[x]);}void join(int x,int y){    int xx=Find(x),yy=Find(y);    if(xx!=yy)        pre[xx]=yy;}double sqr(double x){    return x*x;}double dis(point x,point y){    return sqr(x.x-y.x)+sqr(x.y-y.y);}bool same(int x,int y){    return Find(x)==Find(y);}bool in(point a,point b){    return dis(a,b)<=d*d;}int main(){    int n;    scanf("%d%lf",&n,&d);    map<int,int>Map;    init(n);    for(int i=1;i<=n;i++)        scanf("%lf%lf",&a[i].x,&a[i].y);    char s[2];    while(scanf("%s",s)!=EOF)    {        if(s[0]=='O')        {            int y1;            scanf("%d",&y1);            for(int i=1;i<=n;i++)            {                if(Map[i]>0&&in(a[y1],a[i]))  //电脑修好了,在范围之内                    join(y1,i);            }            Map[y1]++;        }        else        {            int y1,y2;            scanf("%d%d",&y1,&y2);            //cout<<Map[y1]<<" "<<Map[y2]<<endl;            if(Map[y1]>0&&Map[y2]>0&&same(y1,y2))  //两台电脑都是有用的 并且 在同一个连通分量中                puts("SUCCESS");            else                puts("FAIL");        }    }    return 0;}
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