P3976 [TJOI2015]旅游（未完成）

#include<iostream>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<cmath>
using namespace std;
const int maxn=1e6+10;
const int inf=1<<30;
int size[maxn];
int top[maxn];
int dfsx[maxn];
int son[maxn];
int father[maxn];
struct node
{
    int to;
    int next;
}way[maxn<<2];
struct node1
{
    int max;
    int min;
    int ans,ans1;
    node1()
    {
        ans=ans1=max=0;
        min=inf;
    }
}
struct node2
{
    int l,r,ls,rs;
    int min,max;
    int ans,ans1;
    int lazy;
}tree[maxn<<2];
int add(int x,int y)
{
    way[++tot].next=head[x];
    way[tot].to=y;
    head[x]=tot;
}

int dfs1(int x)
{
    size[x]=1;
    for(int i=head[x];i;i=way[i].next)
    {
        int to=way[i].to;
        if(father[x]==to)
        {
            continue;
        }
        deep[to]=deep[x]+1;
        father[to]=x;
        dfs1(to);
        size[x]+=size[to];
        if(size[to]>size[son[x]])
        {
            son[x]=to;
        }
    }
}
int dfs2(int x,int tp)
{
    id[x]=++cnt;
    top[x]=tp;
    value[cnt]=a[x];
    if(son[x])
    {
        dfs2(son[x],tp);
    }
    for(int i=head[x];i;i=way[i].next)
    {
        int to=way[i].to;
        if(to==fa||to==son[x])
        {
            continue;
        }
        dfs2(to,to);
    }
}

inline int pushup(int x)
{
    tree[x].ans=max(tree[tree[x].rs].max-tree[tree[x].ls].min,max(tree[tree[x].ls].ans,tree[tree[x].rs].ans));
    tree[x].ans1=max(tree[tree[x].ls].max-tree[tree[x].rs].min,max(tree[tree[x].ls].ans1,tree[tree[x].rs].ans1);
    tree[x].max=max(tree[tree[x].ls].max,tree[tree[x].rs].max);
    tree[x].min=min(tree[tree[x].ls].min,tree[tree[x].rs].min);
}

int build(int x,int l,int r) 
{
    x=++cnt;
    tree[x].l=l;
    tree[x].r=r;
    if(l==r)
    {
        tree[x].min=tree[x].max=value[l];
        tree[x].ans=tree[x].ans1=0;
        return ;
    }
    int mid=(l+r)>>1;
    build(tree[x].ls,l,mid);
    build(tree[x].rs,mid+1,r);
    pushup(x);
}

inline pushdown(int x)
{
    if(!tree[x].lazy)
    {
        return ;
    }
    tree[tree[x].ls].lazy+=tree[x].lazy;
    tree[tree[x].rs].lazy+=tree[x].lazy;
    tree[tree[x].ls].max+=tree[x].lazy;
    tree[tree[x].rs].max+=tree[x].lazy;
    tree[tree[x].ls].min+=tree[x].lazy;
    tree[tree[x].rs].min+=tree[x].lazy;
    tree[x].lazy=0;
}

node1 pushup1(node1 tmp1,node1 tmp2)
{
    node1 ans1;
    ans1.ans=max(tmp2.max-tmp1.min,max(tmp1.ans,tmp2.ans));
    ans1.ans1=max(tmp1.max-tmp2.min,max(tmp1.ans1,tmp2.ans1));
    ans1.min=min(tmp1.min,tmp2.min);
    ans1.max=max(tmp1.max,tmp2.max);
    return ans1;
}
    
}
node1 update(int x,int l,int r,int val)
{
    if(l<=tree[x].l&&r>=tree[x].r)
    {
        tree[x].lazy+=val;
        tree[x].max+=val;
        tree[x].min+=val;
        node1 ttt;
        ttt.max=tree[x].max;
        ttt.min=tree[x].min;
        ttt.ans=tree[x].ans;
        ttt.ans1=tree[x].ans1;
        return ttt;
    }
    int mid=(tree[x].l+tree[x].r)>>1;
    node1 ttt1;
    node1 ttt2;
    pushdown(x);
    if(l<=mid)
    {
        ttt1=update(tree[x].ls,l,r,val);
    }
    if(r>mid)
    {
        ttt2=update(tree[x].rs,l,r,val);
    }
    pushup(x);
    return pushup1(ttt1,ttt2);
}

int main()
{
    
    return 0;
 }