写了3分之一的树剖板子，然后想调试，然后报错了，so，why？QMQ

#include<bits/stdc++.h>

#define rs id<<1|1
#define ls id<<1





using namespace std;
const int M=5e5+110;
int read(){
	int sum=0,k=1;
	char c=getchar();
	while(c>'9'||c<'0'){if(c=='-')k=-1;c=getchar();}
	while(c>='0'&&c<='9'){sum=sum*10+c-'0';c=getchar();}
	return sum*k;
}
int head[M],chr=0;
struct w{int next,to;}e[M];
void add(int u,int v){e[++chr]={head[u],v};head[u]=chr;}
int size[M],fa[M],deep[M],son[M];
void dfs1(int u,int ft){
	size[u]=1;
	deep[u]=deep[ft]+1;
	for(int i=head[u];i;i=e[i].next){
		int v=e[i].to;
		if(v==ft) continue;
		fa[v]=u;
		size[u]+=size[v];
		if(size[v]>size[son[u]]) son[u]=v;
	}
}
int tap[M],new_id[M],new_val[M],tree_val[M];
int cnt=0;
void dfs2(int u,int top){
	new_id[++cnt]=u;
	new_val[cnt]=tree_val[u];
	tap[u]=top;
	if(son[u]==0) return;
	dfs2(son[u],top);
	for(int i=head[u];i;i=e[i].next){
		int v=e[i].to;
		if(v==fa[u]||v==son[u]) continue;
		dfs2(v,v);
	}
}
struct tree_node{
	int lz,rz,sum;
	int lazy;
}t[M];
void build(int l,int r,int id){
	t[id].lz=l;
	t[id].rz=r;
	if(l==r){
		t[id].sum=new_id[l];
		return ;
	}
	int mid=l+r>>1;
	build(l,mid,ls);
	build(mid+1,r,rs);
	t[id].sum=t[ls].sum+t[rs].sum;
}
void update(){
	t[ls].sum+=(t[ls].rz-t[ls].lz+1)*t[id].lazy;
	t[rs].sum+=(t[rs].rz-t[rs].lz+1)*t[id].lazy;
	t[ls].lazy+=t[id].lazy;
	t[rs].lazy+=t[id].lazy;
	t[id].lazy=0;
	t[id].sum=t[ls].sum+t[rs].sum;
}
signed main(){
	
	
	
	
	return 0;
}

反正马蜂就很抽象

感觉脑袋尖尖的