易看懂的代码，求大佬看看哪里出问题了，样例都过不了

#include <iostream>
using namespace std;
#define ll long long
#define maxn 10000007
ll tree[maxn],lazy[maxn];
int n,m;
string s;
inline void push_up(int node,int left_node,int right_node)
{
	tree[node]=tree[left_node]+tree[right_node];
	return;
}
inline void push_down(int node,int left_node,int right_node,int start,int mid,int end)
{
	lazy[left_node]+=lazy[node];
	lazy[right_node]+=lazy[node];
	if(lazy[node]%2!=0)tree[left_node]=(mid-start+1)-tree[left_node];
	if(lazy[node]%2!=0)tree[right_node]=(end-mid)-tree[right_node];
	lazy[node]=0;
	return;
}
void build_tree(int node,int start,int end)
{
	if(start==end)
	{
		tree[node]=s[start]=='1'?1:0;
		return;
	}
	else
	{
		int mid=(start+end)>>1;
		int left_node=2*node+1;
		int right_node=2*node+2;
		build_tree(left_node,start,mid);
		build_tree(right_node,mid+1,end);
		push_up(node,left_node,right_node);
	}
}
void update_tree(int node,int l,int r,int start,int end)
{
	if(l>end||r<start)return;
	if(l<=start&&r>=end)
	{
		tree[node]=(end-start+1)-tree[node];
		lazy[node]+=1;
		return;
	}
	else
	{
		int left_node=2*node+1;
		int right_node=2*node+2;
		int mid=(start+end)>>1;
		push_down(node,left_node,right_node,start,mid,end);
		update_tree(left_node,l,r,start,mid);
		update_tree(right_node,l,r,mid+1,end);
		push_up(node,left_node,right_node);
		return;
	}
}
ll query(int node,int l,int r,int start,int end)
{
	if(start>=l&&end<=r)return tree[node];
	if(start>r||end<l)return 0;
	else
	{
		int mid=(start+end)>>1;
		int left_node=2*node+1;
		int right_node=2*node+2;
		push_down(node,left_node,right_node,start,mid,end);
		return query(left_node,l,r,start,mid)+query(right_node,l,r,mid+1,end);
	}
}
int main()
{
	cin>>n>>m;
	cin>>s;
	int ch,l,r;
	build_tree(0,0,n-1);
	for(int i=1;i<=m;i++)
	{
		cin>>ch>>l>>r;
		if(ch==0)
		{
			update_tree(0,l,r,0,n-1);
		}
		else if(ch==1)
		{
			cout<<query(0,l,r,0,n-1)<<endl;
		}
	}
	return 0;
}