Luogu P1903 [国家集训队]数颜色 / 维护队列 $带修莫队$

#include <cstdio> 
#include <cstring>
#include <iostream>
#include <algorithm>
#include <cmath>
#define R(a,b,c) for( register int (a) = (b); (a) <= (c); ++(a))
#define nR(a,b,c) for( register int (a) = (b); (a) >= (c); --(a))
#define Max(a,b) ((a) >= (b) ? (a) : (b))
#define Min(a,b) ((a) <= (b) ? (a) : (b))
#define Iv inline void
#define Ii inline int
#define Il inline long long
#define ll long long
#define re register
struct ios{
    template <typename ATP> inline ios& operator >> (ATP &x) {
        x=0; int f=1; char c;
        for (c=getchar(); c<'0' || c>'9'; c=getchar()) if(c == '-') f=-1;
        while (c >= '0' && c <= '9') x = x * 10 + (c ^ '0'), c=getchar();
        x*=f;
        return *this;
    }
    template <typename ATP> inline ios& operator << (ATP x) {
        int digit = 0; char sch[67];
        if( x == 0) { putchar ('0'); return *this;}
        if (x < 0) { x = -x, putchar ('-');}
        while (x) sch[++digit]=x % 10 ^ '0', x /= 10;
        for (register int i=digit; i; --i) putchar (sch[i]);
        return *this;
    }
} io;
using namespace std;
//#define InputAndOutput_Bug_Test
#ifdef InputAndOutput_Bug_Test
int main(){
    while (1) {
        long long x;
        io >> x;
        cout << x << endl;
        io << x;
        putchar ('\n');
    }
}
#endif
const int N=50007;
int col[N];
int TotColor[1000007],NowColor[N];
int block[N];
int ans[N],Ans;
int l=1,r;

struct Query{
    int l,r,tim,id;
    bool operator< (const Query &b)const{
        if(block[l]==block[b.l]){
            if(block[r]==block[b.r])
                return tim<b.tim;
            else
                return r<b.r;
        }
        else
            return l<b.l;
    }
}q[N];

struct Change{
    int pos,New,Old;    
}c[N]; 

Iv Modify(int workColor,int d){
    TotColor[workColor]+=d;
    if(d>0)
        Ans+=(TotColor[workColor]==1);
    if(d<0)
        Ans-=(TotColor[workColor]==0);
}
Iv Going(int pos,int workColor){
    if(l<=pos&&pos<=r){
        Modify(workColor,1),
        Modify(col[pos],-1);
    }
    col[pos]=workColor;
}

int main(){
    int n,m; io>>n>>m;
    int unit=pow(n,0.666666);
    R(i,1,n){
        io>>col[i],
        NowColor[i]=col[i],
        block[i]=(i-1)/unit+1;
    }
    
    int tot=0,Time=0;
    R(i,1,m){
        char opt;
        for(opt=getchar();opt!='Q'&&opt!='R';opt=getchar());
        if(opt=='Q'){
            int l,r;
            io>>l>>r,
            q[++tot]=(Query){l,r,Time,tot};
        }
        else{
            int pos,newColor;
            io>>pos>>newColor,
            c[++Time]=(Change){pos,newColor,NowColor[pos]},
            NowColor[pos]=newColor;
        }
    }
    
    sort(q+1,q+tot+1);
    Time=0;
    R(i,1,tot){
        while(Time<q[i].tim) Going(c[Time+1].pos,c[Time+1].New),++Time;
        while(Time>q[i].tim) Going(c[Time].pos,c[Time].Old),--Time;
        while(l<q[i].l) Modify(col[l],-1),++l;
        while(l>q[i].l) Modify(col[l-1],1),--l;
        while(r<q[i].r) Modify(col[r+1],1),++r;
        while(r>q[i].r) Modify(col[r],-1),--r;
        
        ans[q[i].id]=Ans;
    } 
    
    R(i,1,tot){
        io<<ans[i],
        putchar('\n');
    
    }
    
    return 0;
}