[bzoj3809] Gty的二逼妹子序列

#include<cstdio>
#include<iostream>
#include<cstring>
#include<algorithm>
#include<cmath>
#define ll long long
using namespace std;
const int maxn=100233;
struct zs{int l,r,a,b,id;}q[1002333];
int B[maxn],a[maxn],mp[maxn],l[maxn],r[maxn];
int ans[1002333];
int sz[2333];
int i,j,k,n,m,kuai;

int ra;char rx;
inline int read(){
rx=getchar(),ra=0;
while(rx<'0'||rx>'9')rx=getchar();
while(rx>='0'&&rx<='9')ra*=10,ra+=rx-48,rx=getchar();return ra;
}

inline void add(int x){sz[B[x]]+=!mp[x],mp[x]++;}
inline void del(int x){mp[x]--,sz[B[x]]-=!mp[x];}
inline int query(int a,int b){
register int i;int sm=0,idl=B[a],idr=B[b];
if(idl==idr){
for(i=a;i<=b;i++)sm+=mp[i]>0;
return sm;
}
for(i=a;i<=r[idl];i++)sm+=mp[i]>0;
for(i=l[idr];i<=b;i++)sm+=mp[i]>0;
for(i=idl+1;i<idr;i++)sm+=sz[i];
return sm;
}

bool cmp(zs a,zs b){return B[a.l]==B[b.l]?((B[a.l]&1)?a.r<b.r:a.r>b.r):B[a.l]<B[b.l];}
int main(){
n=read(),m=read();kuai=(int)sqrt(n)+3;
for(i=1;i<=n;i++)a[i]=read(),B[i]=(i+kuai-1)/kuai;
for(i=1;i<=B
;i++)
l[i]=(i-1)*kuai+1,r[i]=i==B
?n:(l[i]+kuai-1);
for(i=1;i<=m;i++)q[i].l=read(),q[i].r=read(),q[i].a=read(),q[i].b=read(),q[i].id=i;
sort(q+1,q+1+m,cmp);
register int l=1,r=0;
for(i=1;i<=m;i++){
while(l>q[i].l)l--,add(a[l]);
while(r<q[i].r)r++,add(a[r]);
while(l<q[i].l)del(a[l]),l++;
while(r>q[i].r)del(a[r]),r--;
ans[q[i].id]=query(q[i].a,q[i].b);
}
for(i=1;i<=m;i++)printf("%d\n",ans[i]);
return 0;
}