BZOJ2836:[SHOI2012]魔法树(树链剖分)

Description

Input

Output

Sample Input

4
0 1
1 2
2 3
4
Add 1 3 1
Query 0
Query 1
Query 2

Sample Output

3
3
2

Solution

退役选手打打板子休闲一下QAQ

居然能1A真是不可思议

Code

#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<algorithm>
#define N (100000+1000)
using namespace std;

struct Edge{int to,next;}edge[N<<1];
struct Node{long long val,add;}Segt[N<<2];

int Depth[N],Father[N],Size[N];
int T_NUM[N],Top[N],Son[N];
int head[N],num_edge;
int x,y,k,n,m,cnt;
char opt[3];

void add(int u,int v)
{
    edge[++num_edge].to=v;
    edge[num_edge].next=head[u];
    head[u]=num_edge;
}

void Dfs1(int x)
{
    Depth[x]=Depth[Father[x]]+1;
    Size[x]=1;
    for (int i=head[x]; i; i=edge[i].next)
        if (edge[i].to!=Father[x])
        {
            Father[edge[i].to]=x;
            Dfs1(edge[i].to);
            Size[x]+=Size[edge[i].to];
            if (!Son[x] || Size[edge[i].to]>Son[x])
                Son[x]=edge[i].to;
        }
}

void Dfs2(int x,int top)
{
    Top[x]=top;
    T_NUM[x]=++cnt;
    if (Son[x]) Dfs2(Son[x],top);
    for (int i=head[x]; i; i=edge[i].next)
        if (edge[i].to!=Father[x] && edge[i].to!=Son[x])
            Dfs2(edge[i].to,edge[i].to);
}

void Pushdown(int now,int l,int r)
{
    if (Segt[now].add)
    {
        Segt[now<<1].add+=Segt[now].add;
        Segt[now<<1|1].add+=Segt[now].add;
        int mid=(l+r)>>1;
        Segt[now<<1].val+=Segt[now].add*(mid-l+1);
        Segt[now<<1|1].val+=Segt[now].add*(r-mid);
        Segt[now].add=0;
    }
}

void Update(int now,int l,int r,int l1,int r1,int k)
{
    if (r<l1 || l>r1) return;
    if (l1<=l && r<=r1)
    {
        Segt[now].val+=(long long)(r-l+1)*k;
        Segt[now].add+=k;
        return;
    }
    Pushdown(now,l,r);
    int mid=(l+r)>>1;
    Update(now<<1,l,mid,l1,r1,k);
    Update(now<<1|1,mid+1,r,l1,r1,k);
    Segt[now].val=Segt[now<<1].val+Segt[now<<1|1].val;
}

long long Query(int now,int l,int r,int l1,int r1)
{
    if (l1<=l && r<=r1)
        return Segt[now].val;
    Pushdown(now,l,r);
    int mid=(l+r)>>1;
    if (r1<=mid) return Query(now<<1,l,mid,l1,r1);
    if (l1>=mid+1) return Query(now<<1|1,mid+1,r,l1,r1);
    return Query(now<<1,l,mid,l1,r1)+Query(now<<1|1,mid+1,r,l1,r1);
}

void Change(int x,int y,int k)
{
    int fx=Top[x],fy=Top[y];
    while (fx!=fy)
    {
        if (Depth[fx]<Depth[fy])
            swap(x,y),swap(fx,fy);
        Update(1,1,n,T_NUM[fx],T_NUM[x],k);
        x=Father[fx],fx=Top[x];
    }
    if (Depth[x]<Depth[y]) swap(x,y);
    Update(1,1,n,T_NUM[y],T_NUM[x],k);
}

int main()
{
    scanf("%d",&n);
    for (int i=1; i<=n-1; ++i)
    {
        scanf("%d%d",&x,&y);
        x++; y++;
        add(x,y); add(y,x);
    }
    Dfs1(1); Dfs2(1,1);
    scanf("%d",&m);
    for (int i=1; i<=m; ++i)
    {
        scanf("%s",opt);
        if (opt[0]=='A')
        {
            scanf("%d%d%d",&x,&y,&k); x++; y++;
            Change(x,y,k);
        }
        else
        {
            scanf("%d",&x); x++;
            printf("%lld
",Query(1,1,n,T_NUM[x],T_NUM[x]+Size[x]-1));
        }
    }
}