Multiplying the tree seeking the maximum or minimum chain

Points by multiplying the maximum value of the chain

inline int LCA(int x,int y)
{
    int maxn=max(w[x],w[y]);
    if (deep[x]>deep[y]) swap(x,y);
    int k=log2(deep[y]);
    for (int i=k;i>=0;i--)
    if (deep[f[i][y]]>=deep[x])
    {
        maxn=max(maxn,maxx[i][y]);
        y=f[i][y];
    }
    if (x==y) return max(maxn,w[x]);
    for (int i=k;i>=0;i--)
    if (f[i][y]!=f[i][x])
    {
        maxn=max(maxn,maxx[i][x]);
        maxn=max(maxn,maxx[i][y]);
        y=f[i][y];
        x=f[i][x];
    }
    return max(maxn,maxx[0][x]);
}
inline void dfs(int x,int fa)
{
    deep[x]=deep[fa]+1;
    f[0][x]=fa;
    maxx[0][x]=w[fa];
    for (int i=1;(1<<i)<=deep[x];i++)
    {
        f[i][x]=f[i-1][f[i-1][x]];
        maxx[i][x]=max(maxx[i-1][x],maxx[i-1][f[i-1][x]]);
    }
    for (int i=head[x];i;i=ed[i].next)
    if (ed[i].e!=fa) dfs(ed[i].e,x);
    return ;
}

Multiplying maximum seek upper chain

inline int LCA(int x,int y)
{
    int maxx=0;
    if (deep[x]>deep[y]) swap(x,y);
    int k=log2(deep[y]);
    for (int i=k;i>=0;i--)
    if (deep[f[i][y]]>=deep[x])
    {
        maxx=max(maxv[i][y],maxx);
        y=f[i][y];
    }
    if (x==y) return maxx;
    for (int i=k;i>=0;i--)
    if (f[i][y]!=f[i][x])
    {
        maxx=max(maxv[i][y],maxx);
        maxx=max(maxv[i][x],maxx);
        y=f[i][y];
        x=f[i][x];
    }
    return max(maxx,max(maxv[0][x],maxv[0][y]));
}
inline void dfs2(int x,int fa)
{
    f[0][x]=fa;
    for (int i=1;(1<<i)<=deep[x];i++)
    {
        f[i][x]=f[i-1][f[i-1][x]];
        maxv[i][x]=max(maxv[i-1][x],maxv[i-1][f[i-1][x]]);
    }
    for (int i=head[x];i;i=ed[i].net)
    if (ed[i].e!=fa) dfs2(ed[i].e,x);
    return ;
}
inline void dfs1(int x,int fa)
{
    deep[x]=deep[fa]+1;
    for (int i=head[x];i;i=ed[i].net)
    if (ed[i].e!=fa) dfs1(ed[i].e,x);
    else maxv[0][x]=ed[i].v;
    return ;
}