bzoj2120

莫队裸题。。

#include<bits/stdc++.h>
#define N 10005
using namespace std;
int qid=0,tim=0,cx[1000005],res,block[N],ans[N],a[N];
struct ask{int l,r,t,id;}q[N];
struct chan{int x,y;}ch[1005];
int cmp(ask a,ask b)
{
    if (block[a.l]==block[b.l])
    {
        if (a.r==b.r) return a.t<b.t;
        else return a.r<b.r;
    }else return a.l<b.l;
}
void change(int now,int i)
{
    if (ch[now].x>=q[i].l && ch[now].x<=q[i].r) 
    {
        cx[a[ch[now].x]]--;
        if (cx[a[ch[now].x]]==0) res--;
        if (cx[ch[now].y]==0) res++;
        cx[ch[now].y]++;            
    }
    swap(a[ch[now].x],ch[now].y);
}
int main()
{
    int n,m,i;
    scanf("%d%d",&n,&m);
    int size=sqrt(n);
    for (i=1;i<=n;i++) scanf("%d",&a[i]),block[i]=(i-1)/size+1;
    for (i=1;i<=m;i++)
    {
        int l,r;char s[5];
        scanf("%s%d%d",s,&l,&r);
        if (s[0]=='Q'){
            q[++qid].l=l; q[qid].r=r; q[qid].id=qid; q[qid].t=tim;
        }
        else ch[++tim].x=l,ch[tim].y=r;
    }
    sort(q+1,q+qid+1,cmp);
    int l=0,r=0,now=0;
    for (i=1;i<=qid;i++)
    {
        while (l<q[i].l){cx[a[l]]--;if (cx[a[l]]==0) res--; l++;}
        while (l>q[i].l){l--;if (cx[a[l]]==0) res++; cx[a[l]]++;}
        while (r<q[i].r){r++;if (cx[a[r]]==0) res++; cx[a[r]]++;}
        while (r>q[i].r){cx[a[r]]--;if (cx[a[r]]==0) res--; r--;}
        while (now<q[i].t){now++;change(now,i);}
        while (now>q[i].t){change(now,i);now--;}
        ans[q[i].id]=res;
    }
    for (i=1;i<=qid;i++)  printf("%d
",ans[i]);
}