RT

#include<iostream>
#include<cstdio>
using namespace std;
const int SIZE=1e5;
int ls(int i){return i<<1;}
int rs(int i){return i<<1|1;}
int _max(int x,int y){return x>y?x:y;}
void _swap(int &x,int &y){int c=x;x=y,y=c;}
int input[SIZE+10],len_;
struct node{
	
	int l,r;
	int sum_0,sum_1,l_0,l_1,r_0,r_1,all_0,all_1;
	int lz_qf,lz_fz;
	
}tree[SIZE*4+10];
node Treetmp[SIZE+10];
int len(int i){return tree[i].r-tree[i].l+1;}

void up(int i){
	
	tree[i].all_0=_max(tree[ls(i)].all_0,_max(tree[rs(i)].all_0,tree[ls(i)].r_0+tree[rs(i)].l_0));
	tree[i].all_1=_max(tree[ls(i)].all_1,_max(tree[rs(i)].all_1,tree[ls(i)].r_1+tree[rs(i)].l_1));
	
}

void update(int i){
	
	tree[i].sum_0=tree[ls(i)].sum_0+tree[rs(i)].sum_0;
	tree[i].sum_1=tree[ls(i)].sum_1+tree[rs(i)].sum_1;
	tree[i].l_0=tree[ls(i)].l_0;tree[i].r_0=tree[rs(i)].r_0;
	tree[i].l_1=tree[ls(i)].l_1;tree[i].r_1=tree[rs(i)].r_1;
	if(len(ls(i))==tree[ls(i)].sum_1) tree[i].l_1+=tree[rs(i)].l_1;
	if(len(rs(i))==tree[rs(i)].sum_1) tree[i].r_1+=tree[ls(i)].r_1;
	up(i);
	
}

void fz0(int i){
	
	tree[i].sum_0=tree[i].l_0=tree[i].r_0=tree[i].all_0=tree[i].r-tree[i].l+1,
	tree[i].sum_1=tree[i].l_1=tree[i].r_1=tree[i].all_1=0;
	
}

void fz1(int i){
	
	tree[i].sum_1=tree[i].l_1=tree[i].r_1=tree[i].all_1=tree[i].r-tree[i].l+1,
	tree[i].sum_0=tree[i].l_0=tree[i].r_0=tree[i].all_0=0;
	
}

void qf(int i){
	
	_swap(tree[i].sum_1,tree[i].sum_0),
	_swap(tree[i].l_1,tree[i].l_0),
	_swap(tree[i].r_1,tree[i].r_0),
	_swap(tree[i].all_1,tree[i].all_0);
	
}

void lztage(int i){
	
	if(tree[i].lz_fz==0) fz0(ls(i)),fz0(rs(i));
	if(tree[i].lz_fz==1) fz1(ls(i)),fz1(rs(i));
	if(tree[i].lz_qf) qf(ls(i)),qf(rs(i));
	if(tree[i].lz_fz!=-1)
	tree[ls(i)].lz_qf=tree[rs(i)].lz_qf=0,tree[ls(i)].lz_fz=tree[rs(i)].lz_fz=tree[i].lz_fz;
//	if(tree[ls(i)].lz_fz!=-1&&tree[i].lz_qf) tree[ls(i)].lz_fz=1-tree[ls(i)].lz_fz;
//	if(tree[rs(i)].lz_fz!=-1&&tree[i].lz_qf) tree[rs(i)].lz_fz=1-tree[rs(i)].lz_fz;
	if(tree[i].lz_qf) tree[ls(i)].lz_qf^=1,tree[rs(i)].lz_qf^=1;
	tree[i].lz_fz=-1,tree[i].lz_qf=0;
	
}

void build(int l,int r,int i){
	
	tree[i].l=l,tree[i].r=r,tree[i].lz_qf=0,tree[i].lz_fz=-1;
	if(l==r)
	{
		tree[i].sum_0=tree[i].l_0=tree[i].r_0=tree[i].all_0=!input[l];
		tree[i].sum_1=tree[i].l_1=tree[i].r_1=tree[i].all_1=input[l];
		return ;
	}
	int mid=(l+r)>>1;
	build(l,mid,ls(i));
	build(mid+1,r,rs(i));
	update(i);
	
}

void change(int l,int r,int i,int opt){
	
	if(tree[i].l>=l&&tree[i].r<=r)
	{
		if(opt==0)
		{
			fz0(i);
			tree[i].lz_qf=0,tree[i].lz_fz=opt;
		}
		if(opt==1)
		{
			 fz1(i);
			 tree[i].lz_qf=0,tree[i].lz_fz=opt;
		}
		if(opt==2)
		{
			 qf(i);
			 tree[i].lz_qf^=1;
		}
		return ;
	}
	lztage(i);
	if(tree[ls(i)].r>=l) change(l,r,ls(i),opt);
	if(tree[rs(i)].l<=r) change(l,r,rs(i),opt);
	update(i);
	
}

int search1(int l,int r,int i){
	
	if(tree[i].l>=l&&tree[i].r<=r) return tree[i].sum_1;
	lztage(i);
	int sum=0;
	if(tree[ls(i)].r>=l) sum+=search1(l,r,ls(i));
	if(tree[rs(i)].l<=r) sum+=search1(l,r,rs(i));
	return sum;
	
}

void search2(int l,int r,int i){
	
	if(tree[i].l>=l&&tree[i].r<=r)
	{
		Treetmp[++len_]=tree[i];
//		printf("%d ",tree[i].all_1);
		return ;
	}
	
	lztage(i);
	
	if(tree[ls(i)].r>=l) search2(l,r,ls(i));
	if(tree[rs(i)].l<=r) search2(l,r,rs(i)); 
	
}

int search3(int i,int s){
	
	if(tree[i].l==tree[i].r) return tree[i].sum_1;
	
	lztage(i);
	if(tree[ls(i)].r>=s) return search3(ls(i),s);
	if(tree[rs(i)].l<=s) return search3(rs(i),s);
	
}//debug

int f(){
	
	int Max=0;
	for(int i=1;i<=len_;i++)
	{
		int nl=Treetmp[i].l_1,j=i;
		while(j<len_&&(Treetmp[j+1].sum_1==(Treetmp[j+1].r-Treetmp[j+1].l+1)))
			nl+=Treetmp[j+1].sum_1,j++;
		Max=_max(Max,_max(Treetmp[i].all_1,nl+Treetmp[j+1].r_1));
	}
	Max=_max(Max,Treetmp[len_].all_1);
	return Max;
	
}//比较笨的查询方法 

void debug(int n){
	
	printf("\n***********************\n");
	for(int i=1;i<=n;i++)
		printf("%d ",search3(1,i));
	printf("\n***********************\n");
	
}

int main(){
	
	int n,m;
	scanf("%d%d",&n,&m);
	
	for(int i=1;i<=n;i++)
		scanf("%d",&input[i]);
	build(1,n,1);
	
	cout<<endl;
	debug(n);
	
	while(m--)
	{
		int opt,l,r;
		scanf("%d%d%d",&opt,&l,&r);
		l++,r++;
		if(opt<=2) change(l,r,1,opt),debug(n);
		else
		{
			if(opt==3) printf("%d",search1(l,r,1)),debug(n);
			if(opt==4)
			{
				len_=0;search2(l,r,1);
				printf("%d",f());
				debug(n);
			}
		}
	}
	
	return 0;
	
}

感谢