bzoj4311向量（线段树分治+斜率优化）

#include<bits/stdc++.h>
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
using namespace std;
typedef long long ll;
const int N=2e5+7;
struct node{int x,y,l,r;}p[N],q[N];
int n,tim,tot,top;
ll ans[N];
vector<node>a[N<<2];
node st[N];
bool cmp(node a,node b){return a.x==b.x?a.y<b.y:a.x<b.x;}
ll dot(node a,node b){return 1ll*a.x*b.x+1ll*a.y*b.y;}
ll cross(node a,node b,node c){return 1ll*(a.x-c.x)*(b.y-c.y)-1ll*(a.y-c.y)*(b.x-c.x);}
void update(int L,int R,int id,int l,int r,int rt)
{
    if(L<=l&&r<=R){a[rt].push_back(p[id]);return;}
    int mid=l+r>>1;
    if(L<=mid)update(L,R,id,lson);
    if(R>mid)update(L,R,id,rson);
}
ll query(int id)
{
    int l=1,r=top,m1,m2;
    ll ret=0;
    while(r-l>=3)
    {
        m1=l+(r-l)/3,m2=r-(r-l)/3;
        if(dot(q[id],st[m1])<=dot(q[id],st[m2]))l=m1;else r=m2;
    }
    for(int i=l;i<=r;i++)ret=max(ret,dot(q[id],st[i]));
    return ret;
}
void work(int x,int l,int r)
{
    if(!a[x].size())return;
    top=0;
    sort(a[x].begin(),a[x].end(),cmp);
    for(int i=0;i<a[x].size();i++)
    {
        while(top>1&&cross(st[top-1],st[top],a[x][i])>=0)top--;
        st[++top]=a[x][i];
    }
    for(int i=l;i<=r;i++)ans[i]=max(ans[i],query(i));
}
void divide(int l,int r,int rt)
{
    work(rt,l,r);
    if(l==r)return;
    int mid=l+r>>1;divide(lson),divide(rson);
}
int main()
{
    scanf("%d",&n);
    for(int i=1,op,x,y;i<=n;i++)
    {
        scanf("%d%d",&op,&x);
        if(op==1)scanf("%d",&y),p[++tot]=(node){x,y,tim+1,-1};
        else if(op==2)p[x].r=tim;
        else scanf("%d",&y),q[++tim]=(node){x,y,tim,tim};
    }
    for(int i=1;i<=tot;i++)if(p[i].r==-1)p[i].r=tim;
    for(int i=1;i<=tot;i++)if(p[i].l<=p[i].r)update(p[i].l,p[i].r,i,1,tim,1);
    divide(1,tim,1);
    for(int i=1;i<=tim;i++)printf("%lld\n",ans[i]);
}