为什么我这份代码的空间不够会RE，数组开大一点就A了

#include<bits/stdc++.h>
#define ll long long
using namespace std;
const int maxn=1e5+9;
ll a[maxn],tree[maxn*4],lazy[maxn*4];//tree存储某个节点区间和 
int n,m;
void build(int l,int r,int fa)//fa表示当前结点的下标 
{
	int mid=(l+r)/2;
	if(l==r)  
	{
		tree[fa]=a[mid];
		return ;
	}
	build(l,mid,fa*2);
	build(mid+1,r,fa*2+1);
	tree[fa]=tree[fa*2]+tree[fa*2+1];
}
ll search(int x,int y,int fa,int l,int r)
{
	int mid=(l+r)/2;
	if(lazy[fa]&&l!=r)
	{
		tree[fa*2]+=(mid-l+1)*lazy[fa];
		tree[fa*2+1]+=(r-mid)*lazy[fa];
		tree[fa]=tree[fa*2]+tree[fa*2+1];
		lazy[fa*2]+=lazy[fa];
		lazy[fa*2+1]+=lazy[fa];
		lazy[fa]=0;
	}
	if(x<=l&&y>=r)
	{
		return tree[fa];
	}
	if(x>=mid+1)
	{
		return search(x,y,fa*2+1,mid+1,r);	
	} 
	else if(y<=mid)
	{
		return search(x,y,fa*2,l,mid);
	}
	else
	{
		return search(x,y,fa*2,l,mid)+search(x,y,fa*2+1,mid+1,r);
	}
}
void change(int x,int y,int fa,int l,int r,ll k)
{	
	int mid=(l+r)/2;
	if(lazy[fa])
	{
		tree[fa*2]+=(mid-l+1)*lazy[fa];
		tree[fa*2+1]+=(r-mid)*lazy[fa];
		lazy[fa*2]+=lazy[fa];
		lazy[fa*2+1]+=lazy[fa];
		lazy[fa]=0;
	}
	
	if(x<=l&&y>=r)
	{
		lazy[fa]+=k; 
		tree[fa]+=(r-l+1)*k;
		return ;
	}

		
	if(x>=mid+1)
	{
		//cout<<"???????";
		change(x,y,fa*2+1,mid+1,r,k);
			
	} 
	else if(y<=mid)
	{
		//cout<<"\\\\\\";	
		change(x,y,fa*2,l,mid,k);		
	}
	else
	{
		//cout<<":::::";
		change(x,y,fa*2,l,mid,k);
		change(x,y,fa*2+1,mid+1,r,k);	
	}
	tree[fa]=tree[fa*2]+tree[fa*2+1];
}
int main()
{
	cin>>n>>m;
	for(int i=1;i<=n;i++)
	{
		scanf("%lld",&a[i]);
	}
	build(1,n,1);
//	int i=1;
//	while(tree[i++])
//	{
//		cout<<tree[i-1]<<" ";
//	}
	while(m--)
	{
		int op;
		scanf("%d",&op);
		if(op==1)
		{
			int x,y;
			ll k;
			scanf("%d %d %lld",&x,&y,&k);
			change(x,y,1,1,n,k);
//			for(int i=1;i<=4*n;i++)
//			{
//				cout<<tree[i]<<" ";
//			}
		//	cout<<"\n";
		}
		else
		{
			int x,y;
			scanf("%d %d",&x,&y);
			printf("%lld\n",search(x,y,1,1,n)); 
		}
	} 
}