自己看：https://blog.csdn.net/weq2011/article/details/128791426

看懂就没问题了

单点修改+区间查询

https://www.luogu.com.cn/problem/P3374

#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N=5e5+5;

int n, m, x, y, op, w[N], k, tr[4*N];
void build(int id, int L, int R)
{
	if (L==R)
	{
		tr[id]=w[L];
		return ;
	}
	
	int mid=(L+R)>>1;
	build(id*2, L, mid);
	build(id*2+1, mid+1, R);
	
	tr[id]=tr[id*2]+tr[id*2+1];
}
void change(int id, int L, int R, int x, int v)
{
	if (L==R)
	{
		tr[id]+=v;
		return ;
	}
	
	int mid=(L+R)>>1;
	if (x<=mid) change(id*2, L, mid, x, v);
	else change(id*2+1, mid+1, R, x, v);
	
	tr[id]=tr[id*2]+tr[id*2+1];
}
int find(int id, int L, int R, int x, int y)
{
	if (x<=L && R<=y) return tr[id];
	
	int mid=(L+R)>>1, res=0;
	if (x<=mid) res+=find(id*2, L, mid, x, y);
	if (y>=mid+1) res+=find(id*2+1, mid+1, R, x, y);
	
	return res;
}
signed main()
{
	scanf("%lld%lld", &n, &m);
	for (int i=1; i<=n; i++) scanf("%lld", &w[i]);
	build(1, 1, n);
	
	for (int i=1; i<=m; i++)
	{
		scanf("%lld", &op);
		if (op==1)
		{
			scanf("%lld%lld", &x, &k);
			change(1, 1, n, x, k);
		}
		else if (op==2)
		{
			scanf("%lld%lld", &x, &y);
			printf("%lld\n", find(1, 1, n, x, y));
		}
	}
	return 0;
}

区间修改+区间查询

https://www.luogu.com.cn/problem/P3372

#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N=1e5+5;

struct node
{
	int lazy, sum;
}tr[4*N];
int n, m, x, y, op, w[N], k;
void build(int id, int L, int R)
{
	if (L==R)
	{
		tr[id].sum=w[L];
		return ;
	}
	
	int mid=(L+R)>>1;
	build(id*2, L, mid);
	build(id*2+1, mid+1, R);
	
	tr[id].sum=tr[id*2].sum+tr[id*2+1].sum;
}
void push_down(int id, int L, int R)
{
	if (tr[id].lazy!=0)
	{
		int mid=(L+R)>>1;
		tr[id*2].lazy+=tr[id].lazy;
		tr[id*2+1].lazy+=tr[id].lazy;
		tr[id*2].sum+=tr[id].lazy*(mid-L+1);
		tr[id*2+1].sum+=tr[id].lazy*(R-(mid+1)+1);
		tr[id].lazy=0;
	}
}
void push_up(int id)
{
	tr[id].sum=tr[id*2].sum+tr[id*2+1].sum;
}
void change(int id, int L, int R, int x, int y, int v)
{
	if (x<=L && R<=y)
	{
		tr[id].lazy+=v;
		tr[id].sum+=v*(R-L+1);
		return ;
	}
	push_down(id, L, R);
	
	int mid=(L+R)>>1;
	if (x<=mid) change(id*2, L, mid, x, y, v);
	if (y>=mid+1) change(id*2+1, mid+1, R, x, y, v);
	
	push_up(id);
}
int find(int id, int L, int R, int x, int y)
{
	if (x<=L && R<=y) return tr[id].sum;
	push_down(id, L, R);
	
	int mid=(L+R)>>1;
	int res=0;
	
	if (x<=mid) res+=find(id*2, L, mid, x, y);
	if (y>=mid+1) res+=find(id*2+1, mid+1, R, x, y);
	
	return res;
}
signed main()
{
	scanf("%lld%lld", &n, &m);
	for (int i=1; i<=n; i++) scanf("%lld", &w[i]);
	build(1, 1, n);
	
	for (int i=1; i<=m; i++)
	{
		scanf("%lld", &op);
		if (op==1)
		{
			scanf("%lld%lld%lld", &x, &y, &k);
			change(1, 1, n, x, y, k);
		}
		else if (op==2)
		{
			scanf("%lld%lld", &x, &y);
			printf("%lld\n", find(1, 1, n, x, y));
		}
	}
	return 0;
}