BZOJ 3809 莫队+（分块｜BIT）

 #include <cstdio>
 #include <iostream>
 #include <cstring>
 #include <algorithm>
 #include <queue>
 #include <vector>
 #include <cmath>
 #define pa pair<int,int>
 #define mp make_pair
 #define fi first
 #define se second
 #define pb push_back
 using namespace std;
 inline void Get_Int(int &x)
 {
     x=;  char ch=getchar(); int f=;
     while (ch<'' || ch>'') {if (ch=='-') f=-; ch=getchar();}
     while (ch>='' && ch<='') {x=x*+ch-''; ch=getchar();} x*=f;
 }
 inline void Put_Int(int x)
 {
     char ch[]; int top=;
     if (x==) ch[++top]='';
     while (x) ch[++top]=x%+'',x/=;
     while (top) putchar(ch[top--]); putchar('\n');
 }
 //===================================================
 const int Maxn=;
 const int Maxm=;
 struct Node{int l,r,u,v,id;}q[Maxm];

 int n,m,s[Maxn],Block,Ans[Maxm],b[Maxn],B[Maxn];//Ans开Maxm
 inline int Get(int x) {return (x-)/Block+;}
 inline int Query(int x,int y)
 {
     int l=Get(x),r=Get(y),ret=;
     if (l==r)
     {
         for (int i=x;i<=y;i++) if (b[i]) ret++;
         return ret;
     }
     for (int i=l+;i<r;i++) ret+=B[i];
     for (int i=x;Get(i)==l;i++) if (b[i]) ret++;
     for (int i=y;Get(i)==r;i--) if (b[i]) ret++;
     return ret;
 }
 inline bool cmp(Node A,Node B)
 {
     if (Get(A.l)==Get(B.l)) return A.r<B.r;
     return Get(A.l)<Get(B.l);
 }
 inline void Del(int x)
 {if (b[s[x]]==) B[Get(s[x])]--; b[s[x]]--;}
 inline void Add(int x)
 {if (b[s[x]]==) B[Get(s[x])]++; b[s[x]]++;}

 int main()
 {
     Get_Int(n),Get_Int(m); Block=(int)sqrt(n);
     for (int i=;i<=n;i++) Get_Int(s[i]);
     for (int i=;i<=m;i++)
         Get_Int(q[i].l),Get_Int(q[i].r),Get_Int(q[i].u),Get_Int(q[i].v),q[i].id=i;
     memset(b,,sizeof(b));
     memset(B,,sizeof(B));
     sort(q+,q+m+,cmp);
     int L=,R=;

     for (int i=;i<=m;i++)
     {
         while (R<q[i].r) R++,Add(R);
         while (L>q[i].l) L--,Add(L);
         while (L<q[i].l) Del(L),L++;
         while (R>q[i].r) Del(R),R--;
         Ans[q[i].id]=Query(q[i].u,q[i].v);
     }
     for (int i=;i<=m;i++) Put_Int(Ans[i]);
     return ;
 }

分块 40s

 #include <cstdio>
 #include <iostream>
 #include <cstring>
 #include <algorithm>
 #include <queue>
 #include <vector>
 #include <cmath>
 #define pa pair<int,int>
 #define mp make_pair
 #define fi first
 #define se second
 #define pb push_back
 using namespace std;
 inline void Get_Int(int &x)
 {
     x=;  char ch=getchar(); int f=;
     while (ch<'' || ch>'') {if (ch=='-') f=-; ch=getchar();}
     while (ch>='' && ch<='') {x=x*+ch-''; ch=getchar();} x*=f;
 }
 inline void Put_Int(int x)
 {
     char ch[]; int top=;
     if (x==) ch[++top]='';
     while (x) ch[++top]=x%+'',x/=;
     while (top) putchar(ch[top--]); putchar('\n');
 }
 //===================================================
 const int Maxn=;
 const int Maxm=;
 struct Node{int l,r,u,v,id;}q[Maxm];

 int c[Maxn],n,m,s[Maxn],Block,Ans[Maxm],b[Maxn];//Ans开Maxm
 inline int lowbit(int x) {return x&(-x);}
 inline int Query(int x)
 {int ret=; for (int i=x;i;i-=lowbit(i)) ret+=c[i];return ret;}
 inline void Modify(int x,int v)
 {for (int i=x;i<=n;i+=lowbit(i)) c[i]+=v;}
 inline int Get(int x) {return (x-)/Block+;}
 inline bool cmp(Node A,Node B)
 {
     if (Get(A.l)==Get(B.l)) return A.r<B.r;
     return Get(A.l)<Get(B.l);
 }
 inline void Del(int x)
 {if (b[s[x]]==) Modify(s[x],-);b[s[x]]--;}
 inline void Add(int x)
 {if (b[s[x]]==) Modify(s[x],); b[s[x]]++;}

 int main()
 {
     Get_Int(n),Get_Int(m); Block=(int)sqrt(n/);
     for (int i=;i<=n;i++) Get_Int(s[i]);
     for (int i=;i<=m;i++)
         Get_Int(q[i].l),Get_Int(q[i].r),Get_Int(q[i].u),Get_Int(q[i].v),q[i].id=i;
     memset(b,,sizeof(b));
     memset(c,,sizeof(c));
     sort(q+,q+m+,cmp);
     int L=,R=;
     for (int i=;i<=m;i++)
     {
         while (R<q[i].r) R++,Add(R);
         while (L>q[i].l) L--,Add(L);
         while (L<q[i].l) Del(L),L++;
         while (R>q[i].r) Del(R),R--;
         Ans[q[i].id]=Query(q[i].v)-Query(q[i].u-);
     }
     for (int i=;i<=m;i++) Put_Int(Ans[i]);
     return ;
 }

BIT 77s

对权值分块复杂度更优.