或者谁帮我找一组 Hack 也行啊。。。

#include<bits/stdc++.h>
using namespace std;

const int N=100005;
int n,m,opt,l,r;

struct SegTree{
	int l,r,sum,maxl0,maxl1,maxr0,maxr1,ans0,ans1,cover;
	bool lazy;
	#define l(x) tree[x].l
	#define r(x) tree[x].r
	#define sum(x) tree[x].sum
	#define maxl0(x) tree[x].maxl0
	#define maxl1(x) tree[x].maxl1
	#define maxr0(x) tree[x].maxr0
	#define maxr1(x) tree[x].maxr1
	#define ans0(x) tree[x].ans0
	#define ans1(x) tree[x].ans1
	#define cover(x) tree[x].cover
	#define lazy(x) tree[x].lazy 
	SegTree(){l=r=sum=maxl0=maxl1=maxr0=maxr1=ans0=ans1=lazy=0;cover=2;}
}tree[N<<3];

void pushdown(int x){
	int l=l(x),r=r(x),mid=l+r>>1;
	if(cover(x)!=2){
		sum(x<<1)=maxl1(x<<1)=maxr1(x<<1)=ans1(x<<1)=(cover(x)?mid-l+1:0);
		sum(x<<1|1)=maxl1(x<<1|1)=maxr1(x<<1|1)=ans1(x<<1|1)=(cover(x)?r-mid:0);
		maxl0(x<<1)=maxr0(x<<1)=ans0(x<<1)=(cover(x)?0:mid-l+1);
		maxl0(x<<1|1)=maxr0(x<<1|1)=ans0(x<<1|1)=(cover(x)?0:r-mid);
		cover(x<<1)=cover(x<<1|1)=cover(x);
		lazy(x<<1)=lazy(x<<1|1)=0;
		cover(x)=2;
	}
	if(!lazy(x))return;
	if(lazy(x<<1)){
		sum(x<<1)=r(x<<1)-l(x<<1)+1-sum(x<<1);
		swap(maxl0(x<<1),maxl1(x<<1));
		swap(maxr0(x<<1),maxr1(x<<1));
		swap(ans0(x<<1),ans1(x<<1));
	}
	if(lazy(x<<1|1)){
		sum(x<<1|1)=r(x<<1|1)-l(x<<1|1)+1-sum(x<<1|1);
		swap(maxl0(x<<1|1),maxl1(x<<1|1));
		swap(maxr0(x<<1|1),maxr1(x<<1|1));
		swap(ans0(x<<1|1),ans1(x<<1|1));
	}
	lazy(x<<1)^=lazy(x);
	lazy(x<<1|1)^=lazy(x);
	lazy(x)=0;
}

void pushup(int x){
	int l=l(x),r=r(x),mid=l+r>>1;
	sum(x)=sum(x<<1)+sum(x<<1|1);
	maxl0(x)=maxl0(x<<1);
	maxl1(x)=maxl1(x<<1);
	if(sum(x<<1)==0)maxl0(x)+=maxl0(x<<1|1);
	else if(sum(x<<1)==mid-l+1)maxl1(x)+=maxl1(x<<1|1);
	maxr0(x)=maxr0(x<<1|1);
	maxr1(x)=maxr1(x<<1|1);
	if(sum(x<<1|1)==0)maxr0(x)+=maxr0(x<<1);
	else if(sum(x<<1|1)==r-mid)maxr1(x)+=maxr1(x<<1);
	ans0(x)=max(max(maxl0(x),maxr0(x)),maxr0(x<<1)+maxl0(x<<1|1));
	ans1(x)=max(max(maxl1(x),maxr1(x)),maxr1(x<<1)+maxl1(x<<1|1));
}

void build(int x,int l,int r){
	if(l==r){
		l(x)=r(x)=l;
		cin>>sum(x);
		if(sum(x)){
			maxl0(x)=maxr0(x)=ans0(x)=0;
			maxl1(x)=maxr1(x)=ans1(x)=1;
		}else{
			maxl0(x)=maxr0(x)=ans0(x)=1;
			maxl1(x)=maxr1(x)=ans1(x)=0;
		}
		return;
	}
	int mid=l+r>>1;
	build(x<<1,l,mid);
	build(x<<1|1,mid+1,r);
	l(x)=l,r(x)=r;
	pushup(x);
}

void COVER(int x,int askl,int askr,bool opt){
	int l=l(x),r=r(x);
	if(askl<=l&&r<=askr){
		if(opt){
			sum(x)=maxl1(x)=maxr1(x)=ans1(x)=r-l+1;
			maxl0(x)=maxr0(x)=ans0(x)=0;
		}else{
			sum(x)=maxl1(x)=maxr1(x)=ans1(x)=0;
			maxl0(x)=maxr0(x)=ans0(x)=r-l+1;
		}
		lazy(x)=0;
		cover(x)=opt;
		return;
	}
	pushdown(x);
	int mid=l+r>>1;
	if(askl<=mid)COVER(x<<1,askl,askr,opt);
	if(askr>mid)COVER(x<<1|1,askl,askr,opt);
	pushup(x);
}

void modify(int x,int askl,int askr){
	int l=l(x),r=r(x);
	int mid=l+r>>1;
	if(askl<=l&&r<=askr){
		lazy(x)^=1;
		if(lazy(x)){
			sum(x)=r-l+1-sum(x);
			swap(maxl0(x),maxl1(x));
			swap(maxr0(x),maxr1(x));
			swap(ans0(x),ans1(x));
		}
		return;
	}
	pushdown(x);
	if(askl<=mid)modify(x<<1,askl,askr);
	if(askr>mid)modify(x<<1|1,askl,askr);
	pushup(x);
}

SegTree query(int x,int askl,int askr){
	int l=l(x),r=r(x);
	if(askl<=l&&r<=askr)return tree[x];
	int mid=l+r>>1;
	pushdown(x);
	if(askr<=mid)return query(x<<1,askl,askr);
	if(askl>mid)return query(x<<1|1,askl,askr);
	SegTree L=query(x<<1,askl,askr),R=query(x<<1|1,askl,askr),ret;
	ret.l=L.l;
	ret.r=R.r;
	ret.sum=L.sum+R.sum;
	ret.ans1=max(max(L.ans1,R.ans1),L.maxr1+R.maxl1);
	ret.maxl1=L.maxl1;
	ret.maxr1=R.maxr1;
	if(L.sum==L.r-L.l+1)ret.maxl1+=R.maxl1;
	if(R.sum==R.r-R.l+1)ret.maxr1+=L.maxr1;
	return ret;
}

int main(){
	cin>>n>>m;
	build(1,1,n);
	while(m--){
		cin>>opt>>l>>r;
		l++,r++;
		if(opt<2)COVER(1,l,r,opt);
		else if(opt==2)modify(1,l,r);
		else if(opt==3)cout<<query(1,l,r).sum<<endl;
		else cout<<query(1,l,r).ans1<<endl;
	}
}