#include <bits/stdc++.h>
using namespace std;
const int N = 1000005;
int n, m, p, x, y, a[N], sum[4 * N];
inline void pushup(int rt)
{
	sum[rt] = sum[rt << 1] + sum[rt << 1 | 1];
}
inline void build(int l, int r, int rt)//建树 
{
	if(l == r){ sum[rt] = a[l]; return;}
	int mid = (l + r) >> 1;
	build(l, mid, rt << 1);
	build(mid + 1, r, rt << 1 | 1);
	pushup(rt);
}
inline void update(int l, int r, int rt, int x, int d)//单点修改 
{
	if(l == r){ sum[rt] = d; return;}
	int mid = (l + r) >> 1;
	if(x <= mid) update(l, mid, rt << 1, x, d);
	else update(mid + 1, r, rt << 1 | 1, x, d);
	pushup(rt);
}
inline int query(int l, int r, int rt, int x, int y)//区间查询 
{
	if(x <= l && r <= y) return sum[rt];//区间[l,r]包含[x,y]
	int mid = (l + r) >> 1;
	int res = 0;
	if(x <= mid) res += query(l, mid, rt << 1, x, y);
	if(y > mid) res += query(mid + 1, r, rt << 1 | 1, x, y);
	return res;
}
int main()
{
    int m, n;
    cin >> m >> n;
    memset(a, 127, sizeof(a));
    for(int i = 1; i <= m; i++) cin >> a[i];
    build(1, m, 1);//建树 
    for(int i = 1; i <= n; i++){
    	cin >> p >> x >> y;
    	if(p == 1) cout << query(1, m, 1, x, y) << " ";
    	else update(1, m, 1, x, y);
	}
    return 0;
}

$Lazytag$

#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N = 1e6 + 1e5;
int n, m, q, l, r, x;
int a[N], add[N], sum[4 * N];
void pushup(int rt)
{
	sum[rt] = sum[rt << 1] + sum[rt << 1 | 1];
}
void pushdown(int rt, int l, int r)
{
	if(add[rt] == 0) return;
	add[rt << 1] += add[rt];
	add[rt << 1 | 1] += add[rt];
	sum[rt << 1] += add[rt] * l;
	sum[rt << 1 | 1] += add[rt] * r;
	add[rt] = 0;
}
void build(int l, int r, int rt)//建树 
{
	if(l == r){ sum[rt] = a[l]; return;}
	int mid = (l + r) >> 1;
	build(l, mid, rt << 1);
	build(mid + 1, r, rt << 1 | 1);
	pushup(rt);
}
void update(int l, int r, int rt, int x, int d)//单点修改 
{
	if(l == r){ sum[rt] = d; return;}
	int mid = (l + r) >> 1;
	if(x <= mid) update(l, mid, rt << 1, x, d);
	else update(mid + 1, r, rt << 1 | 1, x, d);
	pushup(rt);
}
void modify(int x, int y, int d, int l, int r, int rt)//区间修改[x,y]+d 
{
	if(x <= l && y >= r){
		sum[rt] += d * (r - l + 1);//当前的[l,r]都在[x,y]范围内 
		add[rt] += d;//标记
		return; 
	} 
	int mid = (l + r) >> 1;
	pushdown(rt, mid - l + 1, r - mid);
	if(x <= mid) modify(x, y, d, l, mid, rt << 1);
	if(y > mid)  modify(x, y, d, mid + 1, r, rt << 1 | 1);
	pushup(rt);
}
int query(int l, int r, int rt, int x, int y)//区间查询 
{
	if(x > r || y < l) return 0;
	if(x <= l && r <= y) return sum[rt];//区间[x,y]包含[l,r]
	int mid = (l + r) >> 1;
	pushdown(rt, mid - l + 1, r - mid);
	int ans = 0;
	if(x <= mid) ans += query(l, mid, rt << 1, x, y);
	if(y > mid) ans += query(mid + 1, r, rt << 1 | 1, x, y);
	return ans;
}
signed main()
{
    cin >> n >> m;
    for(int i = 1; i <= n; i++) cin >> a[i];
    build(1, n, 1);//建树 
    for(int i = 1; i <= m; i++){
    	cin >> q >> l >> r;
		if(q == 1){
			cin >> x;
			modify(l, r, x, 1, n, 1);
		}	 
		else cout << query(1, n, 1, l, r) << "\n";
	}
    return 0;
}