HDU 2473 Junk-Mail Filter

妥妥的并查集，涉及到节点删除的问题，并且不是完全删除，就是说你扯到的只是这个点，其他点通过这个点建立起来的关系依然存在。

比如我之前知道了AB在同一个集合，BC在同一个集合，现在删掉B之后我仍然认为AC是同一个集合的。这种删除处理起来还算简单吧，其他博客上扯到的虚设父节点，我的理解是直接重新初始化这个节点就好了，反正最后统计的是每个节点现在的父节点。

/*
 Author : Speedcell
 Update : 2013-03-24
Version : soppYcell 2.1(a)
*/

#include <algorithm>
#include <iostream>
#include <fstream>
#include <sstream>
#include <iomanip>

#include <map>
#include <set>
#include <list>
#include <stack>
#include <queue>
#include <deque>
#include <vector>
#include <string>
#include <bitset>
#include <memory>
#include <complex>
#include <numeric>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>
#include <ctype.h>
#include <locale.h>

using namespace std;

#pragma pack(4)

#ifndef __CONSTANT__
#define __CONSTANT__

typedef long long LONG;

const double pi = acos(-1.0);
const int   inf = 0x7f7f7f7f;
const LONG  INF = 0x7f7f7f7f7f7f7f7fll;

const int go[8][2] = {{0,1},{0,-1},{1,0},{-1,0},{1,1},{1,-1},{-1,1},{-1,-1}};

#endif // __CONSTANT__

#ifndef __IO__
#define __IO__

inline bool RD(int    & a) {return scanf("%d",&a)!=EOF;}
inline bool RD(char   & a) {return scanf("%c",&a)!=EOF;}
inline bool RD(char   * a) {return scanf("%s", a)!=EOF;}
inline bool RD(double & a) {return scanf("%lf",&a)!=EOF;}
inline bool RD(LONG   & a) {return scanf("%I64d",&a)!=EOF;}

template<class T1> inline bool
    IN(T1 & a) {return RD(a);}
template<class T1,class T2> inline bool
    IN(T1 & a,T2 & b) {return RD(a)&&RD(b);}
template<class T1,class T2,class T3> inline bool
    IN(T1 & a,T2 & b,T3 & c) {return RD(a)&&RD(b)&&RD(c);}
template<class T1,class T2,class T3,class T4> inline bool
    IN(T1 & a,T2 & b,T3 & c,T4 & d) {return RD(a)&&RD(b)&&RD(c)&&RD(d);}
template<class T1,class T2,class T3,class T4,class T5> inline bool
    IN(T1 & a,T2 & b,T3 & c,T4 & d,T5 & e) {return RD(a)&&RD(b)&&RD(c)&&RD(d)&&RD(e);}
template<class T1,class T2,class T3,class T4,class T5,class T6> inline bool
    IN(T1 & a,T2 & b,T3 & c,T4 & d,T5 & e,T6 & f) {return RD(a)&&RD(b)&&RD(c)&&RD(d)&&RD(e)&&RD(f);}
template<class T1,class T2,class T3,class T4,class T5,class T6,class T7> inline bool
    IN(T1 & a,T2 & b,T3 & c,T4 & d,T5 & e,T6 & f,T7 & g) {return RD(a)&&RD(b)&&RD(c)&&RD(d)&&RD(e)&&RD(f)&&RD(g);}

inline void PT(int    a) {printf("%d",a);}
inline void PT(char   a) {printf("%c",a);}
inline void PT(double a) {printf("%f",a);}
inline void PT(LONG   a) {printf("%I64d",a);}
inline void PT(string a) {printf("%s",a.begin());}

template<class T1> inline void
    OT(T1 a) {PT(a);}
template<class T1,class T2> inline void
    OT(T1 a,T2 b) {PT(a),PT(' '),PT(b);}
template<class T1,class T2,class T3> inline void
    OT(T1 a,T2 b,T3 c) {PT(a),PT(' '),PT(b),PT(' '),PT(c);}
template<class T1,class T2,class T3,class T4> inline void
    OT(T1 a,T2 b,T3 c,T4 d) {PT(a),PT(' '),PT(b),PT(' '),PT(c),PT(' '),PT(d);}
template<class T1,class T2,class T3,class T4,class T5> inline void
    OT(T1 a,T2 b,T3 c,T4 d,T5 e) {PT(a),PT(' '),PT(b),PT(' '),PT(c),PT(' '),PT(d),PT(' '),PT(e);}
template<class T1,class T2,class T3,class T4,class T5,class T6> inline void
    OT(T1 a,T2 b,T3 c,T4 d,T5 e,T6 f) {PT(a),PT(' '),PT(b),PT(' '),PT(c),PT(' '),PT(d),PT(' '),PT(e),PT(' '),PT(f);}
template<class T1,class T2,class T3,class T4,class T5,class T6,class T7> inline void
    OT(T1 a,T2 b,T3 c,T4 d,T5 e,T6 f,T7 g) {PT(a),PT(' '),PT(b),PT(' '),PT(c),PT(' '),PT(d),PT(' '),PT(e),PT(' '),PT(f),PT(' '),PT(g);}

inline void PL(int    a) {printf("%d\n",a);}
inline void PL(char   a) {printf("%c\n",a);}
inline void PL(double a) {printf("%f\n",a);}
inline void PL(LONG   a) {printf("%I64d\n",a);}
inline void PL(string a) {printf("%s\n",a.begin());}

template<class T1> inline void
    OL(T1 a) {PL(a);}
template<class T1,class T2> inline void
    OL(T1 a,T2 b) {PT(a),PT(' '),PL(b);}
template<class T1,class T2,class T3> inline void
    OL(T1 a,T2 b,T3 c) {PT(a),PT(' '),PT(b),PT(' '),PL(c);}
template<class T1,class T2,class T3,class T4> inline void
    OL(T1 a,T2 b,T3 c,T4 d) {PT(a),PT(' '),PT(b),PT(' '),PT(c),PT(' '),PL(d);}
template<class T1,class T2,class T3,class T4,class T5> inline void
    OL(T1 a,T2 b,T3 c,T4 d,T5 e) {PT(a),PT(' '),PT(b),PT(' '),PT(c),PT(' '),PT(d),PT(' '),PL(e);}
template<class T1,class T2,class T3,class T4,class T5,class T6> inline void
    OL(T1 a,T2 b,T3 c,T4 d,T5 e,T6 f) {PT(a),PT(' '),PT(b),PT(' '),PT(c),PT(' '),PT(d),PT(' '),PT(e),PT(' '),PL(f);}
template<class T1,class T2,class T3,class T4,class T5,class T6,class T7> inline void
    OL(T1 a,T2 b,T3 c,T4 d,T5 e,T6 f,T7 g) {PT(a),PT(' '),PT(b),PT(' '),PT(c),PT(' '),PT(d),PT(' '),PT(e),PT(' '),PT(f),PT(' '),PL(g);}

#endif // __IO__

#ifndef __MACRO__
#define __MACRO__

#define ML(times) int tcase; IN(tcase); FOR(times,1,tcase)

#define FOR(i,a,b) for(int i=int(a),_##i=int(b);i<=_##i;i++)
#define DWN(i,b,a) for(int i=int(b),_##i=int(a);_##i<=i;i--)
#define ECH(i,u,pre,next) for(int i=int(pre[u]);i!=-1;i=int(next[i]))

#define MEM(a,v) memset(a,v,sizeof(a))
#define CLR(a,v) FOR(_i##a,0,sizeof(a)/sizeof(a[0])-1) a[_i##a]=v

#define LOOP(a,n)                                               \
    FOR(_i##a,0,(n)-1)                                          \
        cout<<a[_i##a]<<(_i##a!=(n)-1?' ':'\n')
#define LOOP2(a,n,m)                                            \
    FOR(_i##a,0,(n)-1) FOR(_j##a,0,(m)-1)                       \
        cout<<a[_i##a][_j##a]<<(_j##a!=(m)-1?' ':'\n')
#define LOOPG(G,n,pre,next)                                     \
    FOR(_i##a,0,(n)-1) ECH(_j##a,_i##a,pre,next)                \
        cout<<_i##a<<" "<<G[_j##a].v<<" "<<G[_j##a].w<<endl

#endif // __MACRO__

#ifndef __BIT__
#define __BIT__

template<class T> inline T lb(T i) {return i&-i;}
template<class T> inline T lc(T i) {return i<<T(1);}
template<class T> inline T rc(T i) {return i<<T(1)|T(1);}
template<class T> inline T at(T a,int i) {return a& (T(1)<<i);}
template<class T> inline T nt(T a,int i) {return a^ (T(1)<<i);}
template<class T> inline T s1(T a,int i) {return a| (T(1)<<i);}
template<class T> inline T s0(T a,int i) {return a&~(T(1)<<i);}

#endif // __BIT__

#ifndef __DOUBLE__
#define __DOUBLE__

const double eps = 1e-8;

inline int cmp(double a) {return fabs(a-0)<eps?0:((a-0)>eps?+1:-1);}
inline int cmp(double a,double b) {return fabs(a-b)<eps?0:((a-b)>eps?+1:-1);}

inline double fmax(double a,double b) {return cmp(a,b)>0?a:b;}
inline double fmin(double a,double b) {return cmp(a,b)<0?a:b;}

#endif // __DOUBLE__

const int MAXV = 1200000;

class UFS
{
private:
	int Pa[MAXV];
public:
	void clear(void)
	{
		FOR(i,0,MAXV-1) Pa[i]=i;
	}
	int Find(int x)
	{
		if(Pa[x]!=x)
			Pa[x]=Find(Pa[x]);
		return Pa[x];
	}
	void Union(int x,int y)
	{
		int xx=Find(x);
		int yy=Find(y);
		if(xx!=yy) Pa[xx]=yy;
	}
}ufs;

char o;
int n,m,x,y,times=1,name[MAXV];

int main()
{
    #ifndef ONLINE_JUDGE
    freopen("Junk-Mail Filter.txt","r",stdin);
    #else
    #endif

    while(IN(n,m),n+m)
    {
    	ufs.clear();
    	FOR(i,0,n-1) name[i]=i;
    	int label=n;
    	while(m--)
    	{
    		IN(o,o);
    		if(o=='M')
    		{
    			IN(x,y);
    			ufs.Union(name[x],name[y]);
    		}
    		else
    		{
    			IN(x);
    			name[x]=label++;
    		}
    	}
    	set<int> cnt;
    	FOR(i,0,n-1)
    	{
    		cnt.insert(ufs.Find(name[i]));
    	}
    	printf("Case #%d: %d\n",times++,cnt.size());
    }

    return 0;
}