[bzoj2724][Violet 6]蒲公英

http://www.docin.com/p-679227660.html
可以用冰点文库下载..
用分块+可持久化线段树统计答案..
有点毒瘤..

#include 
using namespace std;
#define N 40005
struct lisan
{
    int x,y;
}b[N];
bool cmpli(lisan x,lisan y)
{
    return x.x<y.x;
}
struct tree
{
    int l,r,s;
}tr[666666];
int tottr,rt[N];
int a[N],to[N];
int lb[N],rb[N],f[2005][2005];
int n,block,totblock,ans;
void ins(int &k,int l,int r,int x)
{
    tr[++tottr]=tr[k];
    k=tottr;
    ++tr[k].s;
    if (l==r) return;
    int mid=(l+r)>>1;
    if (x<=mid) ins(tr[k].l,l,mid,x);else ins(tr[k].r,mid+1,r,x);
}
int query(int x,int y,int l,int r,int t)
{
    if (l==r) return tr[y].s-tr[x].s;
    int mid=(l+r)>>1;
    if (t<=mid) return query(tr[x].l,tr[y].l,l,mid,t);
    return query(tr[x].r,tr[y].r,mid+1,r,t);
}
inline int calc(int x,int y,int t)
{
    return query(rt[x-1],rt[y],1,n,t);
}
inline void solve()
{
    int l,r,blol=1,blor=totblock,maxx;
    scanf("%d%d",&l,&r);
    l=(l+ans-1)%n+1;r=(r+ans-1)%n+1;
    if (l>r) swap(l,r);
    if (r-l+1<=2*block)
    {
        maxx=calc(l,r,a[l]);
        ans=a[l];
        for (int i=l+1;i<=r;++i)
        {
            int t=calc(l,r,a[i]);
            if (t>maxx || t==maxx && a[i]printf("%d\n",ans);
        return;
    }
    while (lb[blol]while (rb[blor]>r) --blor;
    ans=f[blol][blor];
    maxx=calc(l,r,ans);
    for (int i=l;iint t=calc(l,r,a[i]);
        if (t>maxx || t==maxx && a[i]for (int i=rb[blor]+1;i<=r;++i)
    {
        int t=calc(l,r,a[i]);
        if (t>maxx || t==maxx && a[i]printf("%d\n",ans);
}
int buc[N];
int main()
{
    int Q;
    cin>>n>>Q;block=200;totblock=(n-1)/block+1;
    for (int i=1;i<=n;++i) scanf("%d",&b[i].x),b[i].y=i;
    sort(b+1,b+1+n,cmpli);int t=0;for (int i=1;i<=n;++i) {if (b[i].x!=b[i-1].x || i==1) ++t;a[b[i].y]=t;to[t]=b[i].x;}
    //for (int i=1;i<=n;++i) cout<' ';cout<for (int i=1;i<=n;++i) rt[i]=rt[i-1],ins(rt[i],1,n,a[i]);
    //cout<<"block="<' '<for (int blo=1;blo<=totblock;++blo) lb[blo]=rb[blo-1]+1,rb[blo]=min(n,lb[blo]+block-1);
    //for (int i=1;i<=totblock;++i) cout<<"lbrb="<' '<for (int i=1;i<=totblock;++i)
    {
    for (int j=1;j<=n;++j) buc[j]=0;
    for (int j=i;j<=totblock;++j)
    {
        for (int k=lb[j];k<=rb[j];++k) ++buc[a[k]];
        int x=lb[i],y=rb[j],t;
        int maxx=calc(x,y,a[lb[j]]);
        f[i][j]=a[lb[j]];
        for (int k=lb[j]+1;k<=rb[j];++k)
        {
            t=buc[a[k]];
            if (t>maxx || t==maxx && a[k]if (ix,y,f[i][j-1]);
            if (t>maxx || t==maxx && f[i][j-1]1];
        }
        //cout<<"ij="<' '<' '<"     xy="<<x<<' '<<y<<"  mx="<while (Q--) solve();
}