#P6611. [Code+#7] 六元环

[Code+#7] 六元环

Problem Description

qwqwq.


Given a sequence a0,a1,…,an,an+1a_0, a_1, \dots, a_n, a_{n+1}, where a0=an+1=+∞a_0 = a_{n+1} = +\infty, and a1,a2,…,ana_1, a_2, \dots, a_n are given in the input.

For 1≤x≤n1 \le x \le n, define max⁡0≤i<x,ai≥axi\max_{0 \le i < x, a_i \ge a_x} i and xx to be adjacent, and define min⁡x<i≤n+1,ai>axi\min_{x < i \le n+1, a_i > a_x} i and xx to be adjacent. If xx and yy are adjacent, then yy and xx are also adjacent.

If 0≤b1,b2,b3,b4,b5,b6≤n+10 \le b_1, b_2, b_3, b_4, b_5, b_6 \le n+1, and bib_i is adjacent to bi+1b_{i+1}, b1b_1 is adjacent to b6b_6, and all bib_i are pairwise distinct, then the set {b1,b2,b3,b4,b5,b6}\{b_1, b_2, b_3, b_4, b_5, b_6\} is called a hexagonal cycle (that is, when judging whether two hexagonal cycles are the same, the order of bib_i is not considered).

There are mm modification operations. Each operation gives x yx\ y, and changes axa_x to ax+ya_x + y. After each modification, you need to output the number of hexagonal cycles.

All values mentioned above are integers, and 1≤n,m≤5×1051 \le n, m \le 5 \times 10^5, 1≤x≤n1 \le x \le n, 1≤ai,y≤1091 \le a_i, y \le 10^9.

Input Format

The first line contains an integer nn.

The second line contains nn integers representing a1,a2,…,ana_1, a_2, \dots, a_n.

The third line contains an integer mm. The next mm lines each contain two integers x yx\ y, representing one modification operation.

Output Format

Output mm lines, each containing one integer, representing the number of hexagonal cycles after each modification.

6
1 2 5 4 3 6
4
1 8
3 6
5 10
2 7
3
0
1
1

Hint

Subtask Score Constraints
11 1010 max⁡(n,m)≤100\max (n,m)\le 100
22 max⁡(n,m)≤2000\max (n,m)\le 2000
33 2020 max⁡(n,m)≤50000\max (n,m)\le 50000
44 for each operation, x≤100x\le 100
55 for each operation, y≤10y\le 10
66

Translated by ChatGPT 5