WA一晚上,AC树链剖分加线段树区间操作

见https://www.luogu.org/record/lists?pid=P3384&uid=&flag=&page=2

wa了一晚上,原来是跳链时的维护反了边，详见代码，哈哈，终于ac了，不容易啊

#include<cstdio>
#include<cstdlib>
#include<iostream>
#define M 110000
#define LL long long
#define reg register
#define REP(i,a,b) for(int i=(int)a; i<=(int)b; ++i)
#define NODES(i,h,a,b) for(int i=a[h]; i; i=b[i])
using namespace std;
int cnt, gen;
int bgn[M], to[M<<1], nxt[M<<1];
LL w[M];
int siz[M], fa[M], top[M], son[M], dep[M];
int ru[M], chu[M];
LL sum[M<<2], addv[M<<2];
int ti, e;
LL mod;
int n, m;
LL asksum;
void edge(int x,int y) {to[e]=y; nxt[e]=bgn[x]; bgn[x]=e; ++e;}
struct Chain
{
  void line(int h, int g, int dep_)
  { 
    siz[h] = 1;
    son[h] = 0;
    fa[h] = g;
    dep[h] = dep_;
    NODES(i,h,bgn,nxt)
    {
      int y = to[i];
      if(y == g) continue;
      line(y, h, dep_+1);
      siz[h] += siz[y];
      if(siz[y] > siz[son[h]]) son[h] = y;
    }
  }

  void zip(int h, int g)
  {
    top[h] = g;
    ru[h] = ++ti;
    if(son[h]) zip(son[h], g);
    NODES(i,h,bgn,nxt)
    {
      int y = to[i];
      if(y == fa[h]) continue;
      if(y == son[h]) continue;
      zip(y, y);
    }
    chu[h] = ti;
  }

  void getchain()
  {
    line(gen, gen, 1);
    zip(gen, gen);
  }
  
  void maintain(int h, int l, int r)
  {
    if(l < r) 
    {
      sum[h] = (sum[(h<<1)] + sum[(h<<1)|1]) % mod;
    }
    if(addv[h])
    {
      sum[h] = (sum[h] + (LL)(r - l + 1) * addv[h]) % mod;
    }
    if(l == r) addv[h] = 0LL;
  }
  
  void pushdown(int h)
  {
    if(addv[h])
    {
      addv[h<<1] += addv[h];
      addv[h<<1] %= mod;
      addv[(h<<1)|1] += addv[h];
      addv[(h<<1)|1] %= mod;
      addv[h] = 0LL;
    }
  }
  
  void add(int h,int l,int r,int y1,int y2,LL v)
  {
    if(y1 <= l && r <= y2)
    {
      addv[h] += v;
      addv[h] %= mod;
    }
    else
    {
      pushdown(h);
      int m = (l + r) >> 1;
      if(y1 <= m) add((h<<1), l, m, y1, y2, v); else maintain((h<<1),l,m); 
      if(m  < y2) add((h<<1)|1,m+1,r, y1, y2, v);else maintain((h<<1)|1,m+1,r);
    }
    maintain(h, l, r);
  }
  
  void query(int h,int l,int r,int y1,int y2,LL add_)
  {
    if(y1 <= l && r <= y2)
    {
      LL p = sum[h] + ((add_) * (LL)(min(r, y2) - max(l, y1) + 1)) % mod;
      asksum += p;
      asksum %= mod;
    }
    else
    {
      int m = (l + r) >> 1;
      if(y1 <= m) query(h<<1, l, m, y1, y2, add_+addv[h]);
      if(m  < y2) query((h<<1)|1, m+1, r, y1, y2, add_+addv[h]);
    }
  }
  
  void getSegmenttree()
  {  
    for(int i=1; i<=n; ++i) 
    {
      add(1, 1, n, ru[i], ru[i], w[i]);
    }
    asksum = 0;
  }
    
  void askson(int h)
  {
    asksum = 0;
    query(1, 1, n, ru[h], chu[h], 0);
    asksum%=mod;
    printf("%lld\n",asksum);
  }
  
  void addson(int h,int v)
  {
    add(1, 1, n, ru[h], chu[h], v);
  }
  
  void askroad(int x,int y)
  {
    asksum = 0;
    while(top[x] != top[y])
    {
      if(dep[top[x]] < dep[top[y]]) swap(x, y);
      query(1, 1, n, ru[top[x]], ru[x], 0);
      asksum%=mod;
      x = fa[top[x]];
    }
    if(dep[x] > dep[y]) swap(x, y);
    query(1, 1, n, ru[x], ru[y], 0);
    asksum%=mod;
    printf("%lld\n",asksum);
  }
  
  void addroad(int x,int y,int v)
  {
    while(top[x] != top[y])
    {
      if(dep[top[x]] < dep[top[y]]) swap(x, y);
      add(1, 1, n, ru[top[x]], ru[x], v);
      asksum%=mod;
      x = fa[top[x]];
    }
    if(dep[x] > dep[y]) swap(x, y);
    add(1, 1, n, ru[x], ru[y], v);
    asksum%=mod;
  }
  
  void work(int m)
  {
    getchain();
    getSegmenttree();
    int ord, x, y;
    LL z;
    while(m--)
    {
      scanf("%d",&ord);
      //printf("%d\n",ord);
      if(ord == 1) { scanf("%d%d%lld",&x,&y,&z); addroad(x, y, z);}
      if(ord == 2) { scanf("%d%d",&x,&y); askroad(x, y);}
      if(ord == 3) { scanf("%d%lld",&x,&z); addson(x, z);}
      if(ord == 4) { scanf("%d",&x); askson(x);}
    }
  }
} tree;

int main()
{
  int x, y, z;
  //freopen("in.txt","r",stdin);
  //freopen("out.txt","w",stdout);
  scanf("%d%d%d%lld",&n,&m,&gen,&mod);
  REP(i, 1, n) scanf("%lld",&w[i]);
  REP(i, 1, n-1)
  {
    scanf("%d%d",&x,&y);
    edge(x, y);
    edge(y, x);
  }
  tree.work(m);
}