[poj 1611]The Suspects[并查集模板][递归与非递归实现]

/*Model One*///364K47MS[poj上递归略快一些~]#include<iostream>#include<cstring>using namespace std;const int MAXSIZE = 30005;int parent[MAXSIZE];//根节点储存-num(该树节点数),子节点储存父节点int Find(int x){//递归的路径压缩    if(parent[x]>=0)    {        parent[x] = Find(parent[x]);        return parent[x];    }    else        return x;}void Union(int root1, int root2){    int x = Find(root1),y = Find(root2);    if(x==y) return;    if(parent[x]<parent[y])    {        parent[x] += parent[y];        parent[y] = x;    }    else{//启发式合并        parent[y] += parent[x];        parent[x] = y;    }}void Init(void){    memset(parent,-1,sizeof(parent));}/*Model Two*///364K63MS#include<iostream>#include<cstring>using namespace std;const int MAXSIZE = 30005;int pre[MAXSIZE];//根节点i,pre[i]=-num,其中num是该树的节点数目                 //非根节点j,pre[j]=k,其中k是j的父节点int Find(int x){//非递归的路径压缩    int p = x;    while(pre[p]>0)  p = pre[p];//找到x的根节点p    while(x!=p){        int tmp = pre[x];//暂存x的父节点        pre[x] = p;//将x的父节点设为根        x = tmp;//沿路径向上压缩    }    return x;//退出时x==p,为根}void Union(int root1,int root2){    int a = Find(root1), b = Find(root2);    if(a==b)  return;    //加权规则合并    if(pre[a]<pre[b])//a的节点数目大于b    {        pre[a] += pre[b];//将b并为a的子树        pre[b] = a;//b已是中间节点,使其父节点为a即可    }    else    {        pre[b] += pre[a];        pre[a] = b;    }}void Init(void){    memset(pre,-1,sizeof(pre));}int main(){    int n,m;    while(cin>>n>>m&&(m+n))    {        if(m==0)        {            cout<<"1"<<endl;            continue;        }        Init();        int sum,x,y;        for(int j=0;j<m;j++)        {            cin>>sum>>x;            for(int i=1;i<sum;i++)            {                cin>>y;                Union(x,y);            }        }        /*Model One*/        //cout<<-parent[Find(0)]<<endl;        /*Model Two*/        cout<<-pre[Find(0)]<<endl;    }    return 0;}