P22663 [USACO] Minimum cost paths
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题目描述

Farmer John's pasture can be regarded as an $N\times M$ ($2\le N\le 10^9$,
$2\le M\le 2\cdot 10^5$) 2D grid of square "cells" (picture a huge chessboard).
The cell at the $x$-th row from the top and $y$-th column from the right is
denoted by $(x,y)$ for each $x\in [1,N], y\in [1,M]$. Furthermore, for each
$y\in [1,M]$, the $y$-th column is associated with the cost $c_y$
($1\le c_y\le 10^9$).

Bessie starts at the cell $(1,1)$. If she is currently located at the cell
$(x,y)$, then she may perform one of the following actions:

If $y<M$, Bessie may move to the next column (increasing $y$ by one) for a
cost of $x^2$.If $x<N$, Bessie may move to the next row (increasing $x$ by one) for a cost
of
$c_y$.
Given $Q$ ($1\le Q\le 2\cdot 10^5$) independent queries each of the form
$(x_i,y_i)$ ($x_i\in [1,N], y_i\in [1,M]$), compute the minimum possible total
cost for Bessie to move from $(1,1)$ to $(x_i,y_i)$.

INPUT FORMAT (input arrives from the terminal / stdin):
The first line contains $N$ and $M$.

The second line contains $M$ space-separated integers $c_1,c_2,\ldots,c_M$.

The third line contains $Q$.

The last $Q$ lines each contain two space-separated integers $x_i$ and $y_i$.

OUTPUT FORMAT (print output to the terminal / stdout):
$Q$ lines, containing the answers for each query.

Note that the large size of integers involved in this problem may require the
use of 64-bit integer data types (e.g., a "long long" in C/C++).

SAMPLE INPUT:
5 4
1 100 100 20
20
1 1
2 1
3 1
4 1
5 1
1 2
2 2
3 2
4 2
5 2
1 3
2 3
3 3
4 3
5 3
1 4
2 4
3 4
4 4
5 4
SAMPLE OUTPUT:
0
1
2
3
4
1
5
11
19
29
2
9
20
35
54
3
13
29
49
69

The output in grid format:

1  2  3  4

--------
1 | 0| 1| 2| 3|
--------
2 | 1| 5| 9|13|
--------
3 | 2|11|20|29|
--------
4 | 3|19|35|49|
--------
5 | 4|29|54|69|
--------

SCORING:
Test cases 1-3 satisfy $N,M\le 2000$.Test cases 4-8 satisfy $c_2>c_3>\cdots>c_M$.Test cases 9-15 satisfy $N\le 2\cdot 10^5$.Test cases 16-20 satisfy no additional constraints.

Problem credits: Benjamin Qi

输入格式

见题面

输出格式

见题面

样例输入
5 4 1 100 100 20 20 1 1 2 1 3 1 4 1 5 1 1 2 2 2 3 2 4 2 5 2 1 3 2 3 3 3 4 3 5 3 1 4 2 4 3 4 4 4 5 4
样例输出
0 1 2 3 4 1 5 11 19 29 2 9 20 35 54 3 13 29 49 69