样例过了，但是交上去爆 $0$。

#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N=100005;
int n,q,a[N];
int sum[N<<2],t1[N<<2],t2[N<<2];
int la[N<<2][2],ra[N<<2][2],ma[N<<2][2];
struct node{int sum,la[2],ra[2],ma[2];};
inline int ls(int p){return p<<1;}
inline int rs(int p){return p<<1|1;}
inline void push_up(int p,int l,int r){
	sum[p]=sum[ls(p)]+sum[rs(p)];
	int mid=(l+r)>>1;
	for(int i=0;i<=1;++i){
		la[p][i]=la[ls(p)][i];
		if(i==1&&sum[ls(p)]==mid-l+1)
			la[p][i]+=la[rs(p)][i];
		else if(i==0&&sum[ls(p)]==0)
			la[p][i]+=la[rs(p)][i];
		ra[p][i]=ra[rs(p)][i];
		if(i==1&&sum[rs(p)]==r-mid)
			ra[p][i]+=ra[ls(p)][i];
		else if(i==0&&sum[ls(p)]==0)
			ra[p][i]+=ra[ls(p)][i];
		ma[p][i]=max(ma[ls(p)][i],ma[rs(p)][i]);
		ma[p][i]=max(ma[p][i],ra[ls(p)][i]+la[rs(p)][i]);
		ma[p][i]=max(ma[p][i],la[ls(p)][i]);
		ma[p][i]=max(ma[p][i],ra[rs(p)][i]);
	}
}
inline void push_down(int p,int l,int r){
	int mid=(l+r)>>1;
	if(t1[p]!=-1){
		t2[p]=0;
		if(t1[p]==1)sum[ls(p)]=mid-l+1,sum[rs(p)]=r-mid;
		else sum[ls(p)]=sum[rs(p)]=0;
		t1[ls(p)]=t1[rs(p)]=t1[p];
		t2[ls(p)]=t2[rs(p)]=0;
		
		la[ls(p)][t1[p]]=ra[ls(p)][t1[p]]=ma[ls(p)][t1[p]]=mid-l+1;
		la[ls(p)][t1[p]^1]=ra[ls(p)][t1[p]^1]=ma[ls(p)][t1[p]^1]=0;
	
		la[rs(p)][t1[p]]=ra[rs(p)][t1[p]]=ma[rs(p)][t1[p]]=r-mid;
		la[rs(p)][t1[p]^1]=ra[rs(p)][t1[p]^1]=ma[rs(p)][t1[p]^1]=0;
		
		t1[p]=-1;
	}
	if(t2[p]){
		sum[ls(p)]=mid-l+1-sum[ls(p)];
		sum[rs(p)]=r-mid-sum[rs(p)];
		
		if(t1[ls(p)]!=-1)t1[ls(p)]^=1;
		else t2[ls(p)]^=1;
		
		if(t1[rs(p)]!=-1)t1[rs(p)]^=1;
		else t2[rs(p)]^=1;
		
		swap(la[ls(p)][0],la[ls(p)][1]);
		swap(ra[ls(p)][0],ra[ls(p)][1]);
		swap(ma[ls(p)][0],ma[ls(p)][1]);
		
		swap(la[rs(p)][0],la[rs(p)][1]);
		swap(ra[rs(p)][0],ra[rs(p)][1]);
		swap(ma[rs(p)][0],ma[rs(p)][1]);
		
		t2[p]=0;
	}
}
inline void build(int p,int l,int r){
	t1[p]=-1;t2[p]=0;
	if(l==r){
		sum[p]=a[l];
		la[p][a[l]]=ra[p][a[l]]=ma[p][a[l]]=1;
		return;
	}
	int mid=(l+r)>>1;
	build(ls(p),l,mid);
	build(rs(p),mid+1,r);
	push_up(p,l,r);
}
inline void update(int p,int l,int r,int L,int R,int k){
	push_down(p,l,r);
	if(L<=l&&r<=R){
		if(k<2){
			t1[p]=k;
			if(k==1)sum[p]=r-l+1;
			else sum[p]=0;
			la[p][k]=ra[p][k]=ma[p][k]=r-l+1;
			la[p][k^1]=ra[p][k^1]=ma[p][k^1]=0;
		}
		else if(k==2){
			sum[p]=r-l+1-sum[p];
			t2[p]^=1;
			swap(la[p][0],la[p][1]);
			swap(ra[p][0],ra[p][1]);
			swap(ma[p][0],ma[p][1]);
		}
		return;
	}
	int mid=(l+r)>>1;
	if(L<=mid)update(ls(p),l,mid,L,R,k);
	if(mid<R)update(rs(p),mid+1,r,L,R,k);
	push_up(p,l,r);
}
inline int query1(int p,int l,int r,int L,int R){
	if(L<=l&&r<=R)
		return sum[p];
	push_down(p,l,r);
	int mid=(l+r)>>1,res=0;
	if(L<=mid)res+=query1(ls(p),l,mid,L,R);
	if(mid<R)res+=query1(rs(p),mid+1,r,L,R);
	return res;
}
inline node query2(int p,int l,int r,int L,int R){
	if(L<=l&&r<=R){
		node ans;
		ans.sum=sum[p];
		for(int i=0;i<=1;++i){
			ans.la[i]=la[p][i];
			ans.ra[i]=ra[p][i];
			ans.ma[i]=ma[p][i];
		}
		return ans;
	}
	push_down(p,l,r);
	int mid=(l+r)>>1;
	if(R<=mid)return query2(ls(p),l,mid,L,R);
	if(mid<L)return query2(rs(p),mid+1,r,L,R);
	node x=query2(ls(p),l,mid,L,R);
	node y=query2(rs(p),mid+1,r,L,R);
	node ans;ans.sum=x.sum+y.sum;
	for(int i=0;i<=1;++i){
		ans.la[i]=x.la[i];
		if(i==1&&x.sum==mid-l+1)
			ans.la[i]+=y.la[i];
		else if(i==0&&x.sum==0)
			ans.la[i]+=y.la[i];
			
		ans.ra[i]=y.ra[i];
		if(i==1&&y.sum==r-mid)
			ans.ra[i]+=x.ra[i];
		else if(i==0&&y.sum==0)
			ans.ra[i]+=x.ra[i];
		
		ans.ma[i]=max(x.ma[i],y.ma[i]);
		ans.ma[i]=max(ans.ma[i],x.ra[i]+y.la[i]);
		ans.ma[i]=max(ans.ma[i],x.la[i]);
		ans.ma[i]=max(ans.ma[i],y.ra[i]);
	}
	return ans;
}
int op,l,r;
signed main(){
	ios::sync_with_stdio(0);
	cin.tie(0),cout.tie(0);
	cin>>n>>q;
	for(int i=1;i<=n;i++)
		cin>>a[i];
	build(1,1,n);
	while(q--){
		cin>>op>>l>>r;
		l++;r++;
		if(op==0){
			update(1,1,n,l,r,0);
		}
		if(op==1){
			update(1,1,n,l,r,1);
		}
		if(op==2){
			update(1,1,n,l,r,2);
		}
		if(op==3){
			cout<<query1(1,1,n,l,r)<<'\n';
		}
		if(op==4){
			node ans=query2(1,1,n,l,r);
			cout<<ans.ma[1]<<'\n';
		}
	}
	return 0;
}