POJ2236 并查集 比1611 复杂一些

这是自己打的  结果第一次就wa了
一直没有找到原因
后来才发现 原来是 数组开小了一个数
原来开成 了 1001
其实开成1002  就能过
#include<stdio.h>
#include<string.h>
int d;
struct node
{
int father;
int xi,yi;
}p[1011];
int find(int x)
{
return x == p[x].father ? x : find(p[x].father);
}
void merge(const node p1,const node p2)
{
int x = find(p1.father);
int y = find(p2.father);
if(x != y)
if((p1.xi - p2.xi)*(p1.xi - p2.xi) + (p1.yi - p2.yi)*(p1.yi - p2.yi) <= d*d)
p[y].father = x;
}
int main()
{
int num,i,n,m;
bool ok[1011];
char pp;
memset(ok,0,sizeof(ok));
scanf("%d%d",&num,&d);
for(i = 1;i <= num ;i++)
p[i].father = i;
for ( i = 1; i <= num ;i++)
scanf("%d%d",&p[i].xi ,&p[i].yi);
while(scanf("\n%c",&pp)!=EOF)
{
if(pp == 'O')
{
scanf("%d",&n);
ok
= 1;
for ( i = 1; i <= num ;i++)
if(ok[i]&& i != n)
merge(p[i],p
);
}
else
{
scanf("%d%d",&m,&n);
if(find(m) == find(n))
printf("SUCCESS\n");
else printf("FAIL\n");
}
}
return 0;
}

#include<string.h>
#include<stdio.h>
#define N 1110
int d;
bool use
;

struct node
{
int pre;
int x, y;
}p
;

int find(int x)
{
return x == p[x].pre ? x : find(p[x].pre);
}

void join(const node p1, const node p2)
{
int root1, root2;
root1 = find(p1.pre);
root2 = find(p2.pre);
if(root1 != root2)
if((p1.x - p2.x) * (p1.x - p2.x) + (p1.y - p2.y) * (p1.y - p2.y) <= d * d)
p[root2].pre = root1;
}

int main()
{
//freopen("Input.txt", "r", stdin);
int num;
char ope;
int ok;
int from, to;
scanf("%d%d", &num, &d);
for(int i = 1; i <= num; ++i)
p[i].pre = i;
memset(use, false, sizeof(use));
for(int i = 1; i <= num; ++i)
scanf("%d%d", &p[i].x, &p[i].y);
while(scanf("\n%c", &ope) != EOF)
{
if(ope == 'O')
{
scanf("%d", &ok);
use[ok] = true;
for(int i = 1; i <= num; ++i)
if(use[i] && i != ok)
join(p[i], p[ok]);
}
else
{
scanf("%d%d", &from, &to);
if(find(from) == find(to))
printf("SUCCESS\n");
else
printf("FAIL\n");
}
}
return 0;
}