[国家集训队]Tree II

题面：

1.树链加;

2.删边加边;

3.树链乘;

4.树链和查询。

还是lct的题。只是标记下传时比较坑。

代码：

#include<cstdio>
#include<algorithm>
using namespace std;
#define MOD 51061
#define N 100050
#define ui unsigned int
ui n,m;
ui fa[N],ch[N][2],vl[N],sum[N],siz[N],mk1[N],mk2[N];
bool res[N],rt[N];
inline ui rd()
{
    ui f = 1,c = 0;char ch = getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch = getchar();}
    while(ch>='0'&&ch<='9'){c=10*c+ch-'0';ch = getchar();}
    return f*c;
}
void reser(ui x)
{
    swap(ch[x][0],ch[x][1]);
    res[x]^=1;
}
void add(ui x,ui d)
{
    vl[x] = (vl[x]+d)%MOD;
    mk1[x]=(mk1[x] + d)%MOD;
}
void mul(ui x,ui d)
{
    vl[x] = (vl[x]*d)%MOD;
    mk2[x]=(mk2[x] * d)%MOD;
}
void update(ui x)
{
    siz[x] = siz[ch[x][0]] + siz[ch[x][1]] + 1;
    sum[x] = ((((sum[ch[x][0]] + sum[ch[x][1]])%MOD)*mk2[x]%MOD + (siz[x]-1)*mk1[x]%MOD)%MOD + vl[x])%MOD;
}
void cal(ui x,ui a,ui b)
{
    vl[x] = (vl[x]*b%MOD + a%MOD)%MOD;
    sum[x] = (sum[x]*b%MOD + siz[x]*a%MOD)%MOD;
    mk1[x] = (mk1[x]*b%MOD + a)%MOD;
    mk2[x] = (mk2[x]*b)%MOD;
}
void pushdown(ui x)
{
    if(res[x])
    {
        reser(ch[x][0]);
        reser(ch[x][1]);
        res[x]=0;
    }
/*    if(mk1[x])
    {
        add(ch[x][0],mk1[x]);
        add(ch[x][1],mk1[x]);
        mk1[x]=0;
    }
    if(mk2[x]!=1)
    {
        mul(ch[x][0],mk2[x]);
        mul(ch[x][1],mk2[x]);
        mk2[x]=1;
    }*/
    if(mk1[x]||mk2[x]!=1)
    {
        cal(ch[x][0],mk1[x],mk2[x]);
        cal(ch[x][1],mk1[x],mk2[x]);
        mk1[x]=0,mk2[x]=1;
    }
}
void down(ui x)
{
    if(!rt[x])down(fa[x]);
    pushdown(x);
}
void rotate(ui x)
{
    ui y = fa[x],k = (ch[y][1]==x);
    if(rt[y])rt[y]=0,rt[x]=1;
    else ch[fa[y]][ch[fa[y]][1]==y] = x;
    fa[x] = fa[y];
    ch[y][k] = ch[x][!k],fa[ch[x][!k]] = y;
    ch[x][!k] = y,fa[y] = x;
    update(y),update(x);
}
void splay(ui x)
{
    down(x);
    while(!rt[x])
    {
        ui y = fa[x],z = fa[y];
        if(!rt[y])
            ((ch[y][1]==x)^(ch[z][1]==y))?rotate(x):rotate(y);
        rotate(x);
    }
}
void access(ui x)
{
    ui y = 0;
    while(x)
    {
        splay(x);
        rt[ch[x][1]] = 1,rt[y] = 0;
        ch[x][1] = y;
        update(x);
        y = x,x = fa[x];
    }
}
void mtr(ui x)
{
    access(x);
    splay(x);
    reser(x);
}
void link(ui x,ui y)
{
    mtr(x);
    fa[x] = y;
}
void cut(ui x,ui y)
{
    mtr(x);
    access(y);
    splay(y);
    ch[y][0] = fa[x] = 0;
    rt[x]=1;
}
void jia(ui u,ui v,ui c)
{
    mtr(u);
    access(v);
    splay(u);
    add(u,c);
}
void cheng(ui u,ui v,ui c)
{
    mtr(u);
    access(v);
    splay(u);
    mul(u,c);
}
ui query(ui u,ui v)
{
    mtr(u);
    access(v);
    splay(u);
    return sum[u];
}
int main()
{
    n = rd(),m = rd();
    for(ui i=1;i<=n;i++)vl[i] = mk2[i] = siz[i] = 1,rt[i] = 1;
    ui u,v,c;
    char cc[2];
    for(ui i=1;i<n;i++)
    {
        u=rd(),v=rd();
        link(u,v);
    }
    for(ui i=1;i<=m;i++)
    {
        scanf("%s",cc);
        if(cc[0]=='+')
        {
            u=rd(),v=rd(),c=rd();
            jia(u,v,c);
        }else if(cc[0]=='-')
        {
            u=rd(),v=rd();
            cut(u,v);
            u=rd(),v=rd();
            link(u,v);
        }else if(cc[0]=='*')
        {
            u=rd(),v=rd(),c=rd();
            cheng(u,v,c);
        }else
        {
            u=rd(),v=rd();
            printf("%u
",query(u,v));
        }
    }
    return 0;
}