[BZOJ 2453]维护队列

#include<cstdio>
#include<algorithm>
#include<cmath>
#define Fast register
inline char Getchar(){
    static char BUF[16384],*S=BUF,*T=BUF;
    return(S==T)&&(T=(S=BUF)+fread(BUF,1,16384,stdin),S==T)?EOF:*S++;
}
inline int Getint(){
    Fast int s=0;Fast char c=Getchar();
    while(c<48||c>57)c=Getchar();
    while(c>47&&c<58)s=s*10+c-48,c=Getchar();
    return s;
}
inline char Getopt(){
    Fast char c=Getchar();
    while(c!=‘Q‘&&c!=‘R‘)c=Getchar();
    return c;
}
int Block[10001];
int Cnt_Query,Cnt_Change;
struct Query{
    int L,R,ID,Time;
    Query():L(0),R(0),ID(0),Time(0){}
    Query(const int&l,const int&r,const int&id,const int&t):L(l),R(r),ID(id),Time(t){}
    inline bool operator<(const Query&T)const{return Block[L]==Block[T.L]?(Block[R]==Block[T.R]?Time<T.Time:R<T.R):L<T.L;}
}query[10001];
struct Change{
    int Pos,Old,New;
    Change():Pos(0),Old(0),New(0){}
    Change(const int&P,const int&O,const int&N):Pos(P),Old(O),New(N){}
}change[1001];
int Cnt[1000001];
int COLOR[10001];
int Now[10001];
int Answer,L=1,R,Time;
int Ans[10001];
inline void update(const int&Color,const int&Delta){
    Cnt[Color]+=Delta;
    if(Delta<0)Answer-=!Cnt[Color];
    if(Delta>0)Answer+=Cnt[Color]==1;
}
inline void Modify(const int&Pos,const int&Color){
    if(L<=Pos&&Pos<=R)update(Color,1),update(COLOR[Pos],-1);
    COLOR[Pos]=Color;
}
#define Qi (query+i)
int main(){
    Fast int N=Getint(),M=Getint(),l,r;
    Fast char c;
    Fast int Unit=pow(N,0.6666666666666666666666666);
    for(Fast int i=1;i<=N;++i)COLOR[i]=Now[i]=Getint(),Block[i]=i/Unit+1;
    for(Fast int i=1;i<=M;++i){
        c=Getopt();l=Getint(),r=Getint();
        if(c==‘Q‘)query[++Cnt_Query]=Query(l,r,Cnt_Query,Cnt_Change);
        else change[++Cnt_Change]=Change(l,Now[l],r),Now[l]=r;
    }
    std::sort(query+1,query+Cnt_Query+1);
    for(Fast int i=1;i<=Cnt_Query;++i){
        while(Time<Qi->Time)++Time,Modify(change[Time].Pos,change[Time].New);
        while(Time>Qi->Time)Modify(change[Time].Pos,change[Time].Old),--Time;
        while(L<Qi->L)update(COLOR[L++],-1);
        while(L>Qi->L)update(COLOR[--L],1);
        while(R<Qi->R)update(COLOR[++R],1);
        while(R>Qi->R)update(COLOR[R--],-1);
        Ans[Qi->ID]=Answer;
    }
    for(Fast int i=1;i<=Cnt_Query;++i)printf("%d\n",Ans[i]);
    return 0;
}