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QOJ

Limite de temps : 6.0 s Limite de mémoire : 1024 MB Points totaux : 100 Hackable ✓

#8074. 先乘后加

Statistiques

给定 $n$ 个数对 $(a_1, b_1), (a_2, b_2), \dots, (a_n, b_n)$,你需要执行 $q$ 次操作。每次操作属于以下两种形式之一:

  • “1 $k$ $a$ $b$” ($1 \le k \le n, 1 \le a, b \le 10^9$):将第 $k$ 个数对修改为 $(a, b)$。
  • “2 $x$ $l$ $r$” ($1 \le x \le 10^9, 1 \le l \le r \le n$):求 $a_i \times x + b_i$ 的最大值,其中 $l \le i \le r$。

输入格式

第一行包含两个整数 $n$ 和 $q$ ($1 \le n, q \le 500\,000$),分别表示数对的数量和操作的数量。

接下来 $n$ 行,每行包含两个整数 $a_i$ 和 $b_i$ ($1 \le a_i, b_i \le 10^9$),表示第 $i$ 个数对。

接下来 $q$ 行,每行描述一个操作,格式如上所述。

输出格式

对于每个查询,输出一行,包含一个整数,表示答案。

样例

输入 1

3 5
2 3
1 5
3 1
2 1 1 3
2 3 1 2
1 3 1 1
2 3 3 3
2 2 1 3

输出 1

6
9
4
7

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