BZOJ3531: [Sdoi2014]旅行

/*
Author:wuhuajun
*/
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <algorithm>
#define lson l, mid, seg[rt].l
#define rson mid+1, r, seg[rt].r
using namespace std;
 
typedef long long ll;
typedef double dd;
const int maxn=200010;
const int maxq = 20000010;
 
int edge, n, fa[maxn], sz[maxn], son[maxn], dep[maxn], hash[maxn], top[maxn];
int h[maxn], num , x, y, tx, ty, Q, a[maxn], b[maxn], node, rel;
char s[22];
 
struct Edge
{
    int to, ne;
} e[maxn * 2];
 
struct Seg
{
    int maxx, sum, l, r;
    void clear()
    {
        maxx = -1000000000;
        sum = 0;
    }
} seg[maxq], ret, ans;
 
 
void close()
{
    exit(0);
}
 
void addedge(int x,int y)
{
    e[edge].to = y;
    e[edge].ne = h[x];
    h[x] = edge++;
}
 
void dfs(int k,int from)
{
    sz[k] = 1;
    son[k] = 0;
    dep[k] = dep[from] + 1;
    for (int p=h[k];p!=-1;p=e[p].ne)
    {
        int to = e[p].to;
        if (from == to) continue;
        fa[to] = k;
        dfs(to, k);
        sz[k] += sz[to];
        if (sz[to] > sz[son[k]]) son[k] = to;
    }
}
 
void build(int k,int from)
{
    hash[k] = ++num;
    top[k] = from;
    if (son[k]) build(son[k], from);
    for (int p=h[k];p!=-1;p=e[p].ne)
    {
        int to = e[p].to;
        if (to != fa[k] && to != son[k])
            build(to, to);
    }
}
 
//{{{Segment部分
void new_node(int rt)
{
    if (seg[rt].l == 0) seg[rt].l = ++node;
    if (seg[rt].r == 0) seg[rt].r = ++node;
}
 
Seg update(Seg a,Seg b)
{
    Seg c;
    c.sum = a.sum + b.sum;
    c.maxx = max(a.maxx, b.maxx);
    return c;
}
 
void pushup(int rt)
{
    seg[rt].maxx = max(seg[seg[rt].l].maxx, seg[seg[rt].r].maxx);
    seg[rt].sum = seg[seg[rt].l].sum + seg[seg[rt].r].sum;
}
 
void change(int L,int R,int val,int l,int r,int rt)
{
    new_node(rt);
    if (L <= l && r <= R)
    {
        seg[rt].sum = seg[rt].maxx = val;
        return;
    }
    int mid = (l + r) >> 1;
    if (L <= mid)
        change(L,R,val,lson);
    if (mid + 1 <= R)
        change(L,R,val,rson);
    pushup(rt);
}
 
Seg query(int L,int R,int l,int r,int rt)
{
    new_node(rt);
    if (L <= l && r <= R)
    {
        return seg[rt];
    }
    int mid = (l + r) >> 1;
    Seg ans;
    ans.clear();
    if (L <= mid)
        ans = update(ans, query(L,R,lson));
    if (mid + 1 <= R)
        ans = update(ans, query(L,R,rson));
    return ans;
}
 
//}}}
 
Seg get_ans()
{
    tx = top[x];
    ty = top[y];
    ans.clear();
    while (tx != ty)
    {
        if (dep[tx] < dep[ty])
        {
            swap(tx, ty);
            swap(x, y);
        }
        ans = update(ans, query(hash[tx], hash[x], 1, n, rel));
        x = fa[tx];
        tx = top[x];
    }
    if (dep[x] > dep[y]) swap(x, y);
    return update(ans, query(hash[x], hash[y], 1, n, rel));
}
 
void init()
{
    scanf("%d %d",&n, &Q);
    memset(h,-1,sizeof(h));
    for (int i=1;i<=n;i++)
    {
        scanf("%d %d",&b[i], &a[i]);
    }
    for (int i=1;i<=n-1;i++)
    {
        scanf("%d %d",&x, &y);
        addedge(x, y);
        addedge(y, x);
    }
    for (int i=1;i<=n;i++)
        scanf("%d", &a[i]);
    dfs(1, 0);
    build(1, 1);
    node = n;
    /*
       for (int i=1;i<=n;i++)
       {
       printf("i:%d top:%d hash:%d\n",i, top[i], hash[i]);
       }
       */
    for (int i=1;i<=n;i++)
        change(hash[i], hash[i], b[i], 1, n, a[i]); // a -> 宗教 b -> 评级
    while (Q--)
    {
        scanf("%s %d %d", s, &x, &y);
        if (s[1] == ‘C‘)
        {
            change(hash[x], hash[x], 0, 1, n, a[x]); //把本属于宗教a[i]的x点评级改成0;
            a[x] = y;
            change(hash[x], hash[x], b[x], 1, n, a[x]); //把本属于宗教a[i]的x点评级改成现有的
        }
        if (s[1] == ‘W‘)
        {
            b[x] = y;
            change(hash[x], hash[x], y, 1, n, a[x]);
        }
        if (s[1] == ‘S‘)
        {
            rel = a[x];
            ret = get_ans();
            printf("%d\n", ret.sum);
        }
        if (s[1] == ‘M‘)
        {
            rel = a[x];
            ret = get_ans();
            printf("%d\n", ret.maxx);
        }
    }
}
 
int main ()
{
    init();
    close();
    return 0;
}