AC日记——[SDOI2017]相关分析 洛谷 P3707

[SDOI2017]相关分析

思路：

　　裸线段树；

　　（玄学ac）；

代码：

#include <bits/stdc++.h>
using namespace std;
#define maxn 100005
struct TreeNodeType {
    int l,r,mid;
    double flagx2,flagy2,flagx3,flagy3,size;
    double sumx,sumy,suml,sumxy,sumx2,sumy2,suml2;
    bool if_3;
    inline void updata2(double posx,double posy)
    {
        sumx2+=size*posx*posx+*posx*sumx;
        sumy2+=size*posy*posy+*posy*sumy;
        sumxy+=size*posx*posy+sumx*posy+sumy*posx;
        sumx+=size*posx,sumy+=size*posy;
        flagx2+=posx,flagy2+=posy;
    }
    inline void updata3(double posx,double posy)
    {
        sumxy=size*posx*posy+suml*(posx+posy)+suml2;
        sumx2=size*posx*posx+posx**suml+suml2;
        sumy2=size*posy*posy+posy**suml+suml2;
        sumx=size*posx+suml,sumy=size*posy+suml;
        if_3=true,flagx3=posx,flagy3=posy;
        flagx2=,flagy2=;
    }
};
struct TreeNodeType tree[maxn<<];
int n,m;
double Sumx,Sumy,Sumx2,Sumy2,Sumxy,ai[maxn],bi[maxn];
inline void updata(int now)
{
    tree[now].sumx=tree[now<<].sumx+tree[now<<|].sumx;
    tree[now].sumy=tree[now<<].sumy+tree[now<<|].sumy;
    tree[now].suml=tree[now<<].suml+tree[now<<|].suml;
    tree[now].sumxy=tree[now<<].sumxy+tree[now<<|].sumxy;
    tree[now].sumx2=tree[now<<].sumx2+tree[now<<|].sumx2;
    tree[now].sumy2=tree[now<<].sumy2+tree[now<<|].sumy2;
    tree[now].suml2=tree[now<<].suml2+tree[now<<|].suml2;
}
void build(int now,int l,int r)
{
    tree[now].l=l,tree[now].r=r,tree[now].size=r-l+;
    if(l==r)
    {
        tree[now].sumx=ai[l],tree[now].sumy=bi[l],tree[now].suml=l;
        tree[now].sumxy=ai[l]*bi[l],tree[now].suml2=(double)l*l;
        tree[now].sumx2=ai[l]*ai[l],tree[now].sumy2=bi[l]*bi[l];
        return;
    }
    tree[now].mid=l+r>>;
    build(now<<,l,tree[now].mid);
    build(now<<|,tree[now].mid+,r);
    updata(now);
}
inline void pushdown(int now)
{
    if(tree[now].if_3)
    {
        tree[now].if_3=false;
        tree[now<<].updata3(tree[now].flagx3,tree[now].flagy3);
        tree[now<<|].updata3(tree[now].flagx3,tree[now].flagy3);
    }
    if(tree[now].flagx2||tree[now].flagy2)
    {
        tree[now<<].updata2(tree[now].flagx2,tree[now].flagy2);
        tree[now<<|].updata2(tree[now].flagx2,tree[now].flagy2);
        tree[now].flagx2=,tree[now].flagy2=;
    }
}
void operation1(int now,int l,int r)
{
    if(tree[now].l>=l&&tree[now].r<=r)
    {
        Sumx+=tree[now].sumx,Sumy+=tree[now].sumy;
        Sumx2+=tree[now].sumx2,Sumy2+=tree[now].sumy2;
        Sumxy+=tree[now].sumxy;return;
    }
    if(tree[now].if_3||tree[now].flagx2||tree[now].flagy2) pushdown(now);
    if(l<=tree[now].mid) operation1(now<<,l,r);
    if(r>tree[now].mid) operation1(now<<|,l,r);
}
void operation2(int now,int l,int r,double s,double t)
{
    if(tree[now].l>=l&&tree[now].r<=r)
    {
        tree[now].updata2(s,t);
        return;
    }
    if(tree[now].if_3||tree[now].flagx2||tree[now].flagy2) pushdown(now);
    if(l<=tree[now].mid) operation2(now<<,l,r,s,t);
    if(r>tree[now].mid) operation2(now<<|,l,r,s,t);
    updata(now);
}
void operation3(int now,int l,int r,double s,double t)
{
    if(tree[now].l>=l&&tree[now].r<=r)
    {
        tree[now].updata3(s,t);
        return;
    }
    if(tree[now].if_3||tree[now].flagx2||tree[now].flagy2) pushdown(now);
    if(l<=tree[now].mid) operation3(now<<,l,r,s,t);
    if(r>tree[now].mid) operation3(now<<|,l,r,s,t);
    updata(now);
}
int main()
{
    scanf("%d%d",&n,&m);
    for(int i=;i<=n;i++) scanf("%lf",&ai[i]);
    for(int i=;i<=n;i++) scanf("%lf",&bi[i]);
    build(,,n);
    int op,l,r;double s,t;
    while(m--)
    {
        scanf("%d%d%d",&op,&l,&r);
        if(op==)
        {
            Sumx=,Sumy=,Sumxy=,Sumx2=,Sumy2=;
            operation1(,l,r);
            double size=r-l+,x_=Sumx/size,y_=Sumy/size;
            double a=Sumxy-Sumy*x_-Sumx*y_+y_*x_*size;
            double b=Sumx2-*Sumx*x_+x_*x_*size;
            printf("%.10lf\n",a/b);
        }
        if(op==) scanf("%lf%lf",&s,&t),operation2(,l,r,s,t);
        if(op==) scanf("%lf%lf",&s,&t),operation3(,l,r,s,t);
    }
    return ;
}