https://www.luogu.com.cn/record/184103679

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
ll n,m;
ll d[3000001],a[100002],b[3000001];
void build(int s,int t,int p)
{
	if(s==t)
	{
		d[p]=a[s];
		return;
	}
	int m=(s+t)/2;
	build(s,m,2*p);
	build(m+1,t,2*p+1);
	d[p]=d[p*2]+d[p*2+1]; 
}
int getsum(int l,int r,int s,int t,int p)
{
	if(l<=s and r>=t) return d[p];
	int m=(t+s)/2,sum=0;
	if(b[p])
	{
		b[2*p]+=b[p];b[2*p+1]+=b[p];
		d[2*p]+=b[p]*(m-s+1);d[2*p+1]+=b[p]*(t-m);
		b[p]=0;
	}
	if(l<=m) sum+=getsum(l,r,s,m,2*p);
	if(r>=m+1) sum+=getsum(l,r,m+1,t,2*p+1);
	return sum;
}
void upset(int l,int r,int c,int s,int t,int p)
{
	if(l<=s and r>=t)
	{
		d[p]+=c*(t-s+1);
		b[p]+=c;
		return ;
	}
	int m=(t+s)/2;
	if(b[p] and s!=t)
	{
		b[2*p]+=b[p],b[2*p+1]+=b[p];
		d[2*p]+=b[p]*(m-s+1),d[2*p+1]+=b[p]*(t-m);
		b[p]=0; 
	}
	if(l<=m) upset(l,r,c,s,m,2*p);
	if(r>m) upset(l,r,c,m+1,t,2*p+1);
	d[p]=d[2*p]+d[2*p+1];
}
int main()
{
	cin>>n>>m;
	for(int i=1;i<=n;i++) cin>>a[i];
	build(1,n,1);
	while(m--)
	{
		int nu; cin>>nu;
		if(nu==1)
		{
			ll x,y,k;
			cin>>x>>y>>k;
			upset(x,y,k,1,n,1);
		}
		else
		{
			ll x,y;
			cin>>x>>y;
			cout<<getsum(x,y,1,n,1)<<endl;
		}
	}
	return 0;
}

感谢