P3258 [JLOI2014]松鼠的新家

P3258 [JLOI2014]松鼠的新家
倍增lca+树上差分，从叶子节点向根节点求前缀和，dfs求子树和即可，最后，把每次的起点和终点都。

#include<iostream>
#include<cstdio>
#include<queue>
#include<algorithm>
#include<cmath>
#include<ctime>
#include<set>
#include<map>
#include<stack>
#include<cstring>
#define inf 2147483647
#define For(i,a,b) for(register int i=a;i<=b;i++)
#define p(a) putchar(a)
#define g() getchar()
//by war
//2017.11.8
using namespace std;
int f[300010][20];
int a[300010],b[300010];
int deep[300010];
int change[300010];
bool vis[300010];
int lca;
int x,y;
int n;
struct node
{
    int n;
    node *next;
}*e[600010];

inline void in(register int &x)
{
    int y=1;
    char c=g();x=0;
    while(c<'0'||c>'9')
    {
    if(c=='-')
    y=-1;
    c=g();
    }
    while(c<='9'&&c>='0')x=(x<<1)+(x<<3)+c-'0',c=g();
    x*=y;
}
inline void o(register int x)
{
    if(x<0)
    {
        p('-');
        x=-x;
    }
    if(x>9)o(x/10);
    p(x%10+'0');
}

inline void push(register int x,register int y)
{
    node *p;
    p=new node();
    p->n=y;
    if(e[x]==NULL)
    e[x]=p;
    else
    {
        p->next=e[x]->next;
        e[x]->next=p;
    }
}

inline void build(register int now)
{
    deep[now]=deep[f[now][0]]+1;
    for(register int i=1;(1<<i)<=n;i++)
    f[now][i]=f[f[now][i-1]][i-1];
    for(node *i=e[now];i!=NULL;i=i->next)
    {
        if(f[now][0]!=i->n)
        {
            f[i->n][0]=now;
            build(i->n);
        }
    }
}

inline int query(register int x,register int y)
{
    if(deep[x]<deep[y])
    swap(x,y);
    int c=deep[x]-deep[y];
    for(register int i=0;(1<<i)<=c;i++)
    if((1<<i)&c)
    x=f[x][i];
    if(x==y)
    return x;
    for(register int i=log2(deep[x]);i>=0;i--)
    {
        if(f[x][i]!=f[y][i])
        {
            x=f[x][i];
            y=f[y][i];
        }
    }
    return f[x][0];
}

int dfs(int now)
{
    if(vis[now])
    return b[now];
    vis[now]=true;
    for(node *i=e[now];i!=NULL;i=i->next)
    if(!vis[i->n])
    {
    x=dfs(i->n);
    b[now]+=x;
    }
    return b[now];
}

int main()
{
//    freopen("t.in","r",stdin);
//    freopen("t2.out","w",stdout);
    in(n);
    For(i,1,n)
    in(a[i]);
    For(i,1,n-1)
    {
        in(x),in(y);
        push(x,y);
        push(y,x);
    }
//    f[0][0]=0;
    build(1);
    For(i,1,n-1)
    {
        x=a[i];
        y=a[i+1];
        lca=query(x,y);
        change[x]++;
        change[y]++;
        change[lca]--;
        change[f[lca][0]]--;
    } 
    For(i,1,n)
    b[i]=change[i];
    b[1]=dfs(1); 
    For(i,2,n)
    b[a[i]]--;
    For(i,1,n)
    o(b[i]),p('
');
     return 0;
}