并查集_hash_HDU_1856

简单hash一下，在进行并查集操作

//并查集中，元素最多的是几个
#include
#include
#define Mod 100007
#define Max(a,b) (a)>(b)?(a):(b)
const int maxn = 100005;
struct node
{
    int id,ha,next;
};
node e[maxn];
int par[maxn], rot[maxn], num[maxn];
int h[maxn],tot,head[maxn];
void Init()
{
   // memset(head, -1 sizeof(head));
    tot = 0;
    for(int i = 0; i < maxn; i++)
    {
        par[i] = i;
        rot[i] = 0;
        num[i] = 1;
        head[i] = -1;
    }
}
int Hash(int x)
{
    int t = x % Mod;
    for(int i = head[t]; i != -1; i=e[i].next)
        if(e[i].id == x )
          return i;
    e[tot].id = x;
    e[tot].ha = t;
    e[tot].next = head[t];
    head[t] = tot++;
    return tot-1;
}
int Find(int x)
{
    if(x == par[x])
        return x;
    par[x] = Find(par[x]);
    return par[x];
}
void Union(int x, int y)
{
    x = Find(x);
    y = Find(y);
    if(x == y)return;
    if(rot[x]>rot[y])
    {
        par[y] = x;
        num[x]+=num[y];
    }
    else
    {
        par[x] = y;
        rot[y]++;
        num[y]+=num[x];
    }
}
int main()
{
    int n,u,v;
    while(scanf("%d",&n) != EOF)
    {
        Init();
        for(int i = 0; i < n; i++)
        {
            scanf("%d%d",&u,&v);
            u = Hash(u);
            v = Hash(v);
            Union(u,v);
        }
        int ret = 0;
        for(int i = 0; i < maxn; i++)
            ret = Max(ret, num[i]);
        printf("%d\n",ret);
    }
    return 0;
}