#include <cstdio>
const int Maxn=;
inline void Get_Int(int &x)
{
char ch=getchar(); x=;
while (ch<'' || ch>'') ch=getchar();
while (ch>='' && ch<='') {x=x*+ch-''; ch=getchar();}
}
struct Node
{
Node * l,* r; int Sum;
inline void Push_Up() {Sum=l->Sum+r->Sum;}
};
Node Memory[Maxn*],* port=Memory,* null,* Root[Maxn];
int n,m,Mx,a[Maxn],l,r;
inline int Max(int x,int y) {return x>y?x:y;}
inline void Init() {null=port++; null->Sum=; null->l=null->r=null;}
inline Node * NewNode(Node * x)
{
Node * Ret=port++;
if (x==null) {Ret->l=Ret->r=null; Ret->Sum=;} else
{Ret->l=x->l,Ret->r=x->r,Ret->Sum=x->Sum;}
return Ret;
} Node * Insert(Node * Pre,int o,int l,int r,int v)
{
Node * Ret=NewNode(Pre);
if (l==r)
{
Ret->Sum+=v;
return Ret;
}
int mid=(l+r)>>;
if (v<=mid) Ret->l=Insert(Pre->l,o<<,l,mid,v); else Ret->r=Insert(Pre->r,o<<|,mid+,r,v);
Ret->Push_Up();
}
int Sum(Node * Now,int o,int l,int r,int p,int q)
{
if (Now==null) return ;
if (l==p && r<=q) return Now->Sum;
int mid=(l+r)>>;
if (q<=mid) return Sum(Now->l,o<<,l,mid,p,q);
if (p>=mid+) return Sum(Now->r,o<<|,mid+,r,p,q);
if (p<=mid && q>=mid+) return Sum(Now->l,o<<,l,mid,p,mid)+Sum(Now->r,o<<|,mid+,r,mid+,q);
}
inline int Query(int L,int R)
{
int Ret=;
while (true)
{
int t=Sum(Root[R],,,Mx,,Ret)-Sum(Root[L],,,Mx,,Ret);
if (t<Ret) return Ret; else Ret=t+;
}
return Ret;
}
int main()
{
// freopen("data.in","r",stdin);
// freopen("data.out","w",stdout);
Init();
Get_Int(n);
for (int i=;i<=n;i++) Get_Int(a[i]),Mx=Max(Mx,a[i]);
Root[]=NewNode(null);
for (int i=;i<=n;i++) Root[i]=Insert(Root[i-],,,Mx,a[i]);
Get_Int(m);
for (int i=;i<=m;i++)
{
Get_Int(l),Get_Int(r);
printf("%d\n",Query(l-,r));
}
return ;
}
C++
网上题解一堆..即找到1~Mx.那么1~Mx的Sum就都可以取到.
BZOJ上问Root讨来数据自测全A,交上去WA.