Score : $100$ points

问题描述

存在一个包含 $H$ 行（水平方向）和 $W$ 列（垂直方向）的网格。令 $(i,j)$ 表示从上到下的第 $i$ 行、从左到右的第 $j$ 列的方格。

找出与方格 $(R, C)$ 共享边的方格数量。

这里，两个方格 $(a,b)$ 和 $(c,d)$ 被认为共享一条边当且仅当 $|a-c|+|b-d|=1$（其中 $|x|$ 表示 $x$ 的绝对值）。

以上为通义千问 qwen-max 翻译，仅供参考。

Problem Statement

There is a grid with $H$ horizontal rows and $W$ vertical columns. Let $(i,j)$ denote the square at the $i$-th row from the top and the $j$-th column from the left.
Find the number of squares that share a side with Square $(R, C)$.

Here, two squares $(a,b)$ and $(c,d)$ are said to share a side if and only if $|a-c|+|b-d|=1$ (where $|x|$ denotes the absolute value of $x$).

Constraints

• All values in input are integers.
• $1 \le R \le H \le 10$
• $1 \le C \le W \le 10$

Input

Input is given from Standard Input in the following format:

$H$ $W$

$R$ $C$

Output

Print the answer as an integer.

Sample Input 1

3 4
2 2

Sample Output 1

4

We will describe Sample Inputs/Outputs $1,2$, and $3$ at once below Sample Output $3$.

Sample Input 2

3 4
1 3

Sample Output 2

3

Sample Input 3

3 4
3 4

Sample Output 3

2

When $H=3$ and $W=4$, the grid looks as follows.

• For Sample Input $1$, there are $4$ squares adjacent to Square $(2,2)$.
• For Sample Input $2$, there are $3$ squares adjacent to Square $(1,3)$.
• For Sample Input $3$, there are $2$ squares adjacent to Square $(3,4)$.

Sample Input 4

1 10
1 5

Sample Output 4

2

Sample Input 5

8 1
8 1

Sample Output 5

1

Sample Input 6

1 1
1 1

Sample Output 6

0

update @ 2024/3/10 10:40:28