poj2236
简单并查集
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
using namespace std;
#define maxn 1005
#define eps 1.0e-8
struct Computer
{
int x, y;
bool r;
}computer[maxn];
int n, d;
int father[maxn];
int getanc(int a)
{
if (father[a] == a)
return a;
return father[a] = getanc(father[a]);
}
void merge(int a, int b)
{
father[getanc(a)] = getanc(b);
}
double dis(Computer &a, Computer &b)
{
return sqrt((a.x - b.x) *(a.x - b.x) +(a.y - b.y) *(a.y - b.y));
}
void make(int a)
{
computer[a].r = true;
for (int i = 0; i < n; i++)
if (computer[i].r && dis(computer[i], computer[a]) < d + eps)
merge(i, a);
}
int main()
{
//freopen("t.txt", "r", stdin);
scanf("%d%d", &n, &d);
for (int i = 0; i < n; i++)
{
father[i] = i;
scanf("%d%d", &computer[i].x, &computer[i].y);
computer[i].r = false;
}
getchar();
char ch;
int a, b;
while (scanf("%c", &ch) != EOF)
{
if (ch == 'O')
{
scanf("%d", &a);
a--;
getchar();
make(a);
}else
{
scanf("%d%d", &a, &b);
a--;
b--;
getchar();
if (getanc(a) == getanc(b))
printf("SUCCESS\n");
else
printf("FAIL\n");
}
}
return 0;
}