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);}