P30034 [洛谷] [COCI 2023/2024 #1] Labyrinth
普及+
题目描述

Problem Background

Teo and the Croatian EJOI team are inside a labyrinth.

Problem Description

The labyrinth is an $n \times m$ grid, with coordinates $(1,1)$ representing the top-left cell and coordinates $(n,m)$ representing the bottom-right cell. Each pair of adjacent (four-connected, i.e., adjacent to the top, bottom, left, or right) cells has a door. These doors come in four colors: blue, red, green, and orange, represented by the characters P, C, Z, and N, respectively. Movement between cells is only possible through these doors.

Teo will give you $q$ queries. Each query specifies $a, b, c, d$, asking for the shortest path from $(a, b)$ to $(c, d)$ while minimizing the number of distinct door colors passed through. You are to answer the minimum number of distinct colors required.

Input Format

The first line contains two integers $n$ and $m$, representing the number of rows and columns of the grid.

The next $n$ lines, each with $m-1$ characters, describe the horizontal doors between cells $(i, j)$ and $(i, j+1)$.

The following $n-1$ lines, each with $m$ characters, describe the vertical doors between cells $(i, j)$ and $(i+1, j)$.

The next line contains an integer $q$, the number of queries.

The following $q$ lines each contain four integers $a_i, b_i, c_i, d_i$, representing the query for the minimum number of distinct door colors from $(a_i, b_i)$ to $(c_i, d_i)$.

Output Format

Output $q$ lines, each containing a single integer representing the answer to the corresponding query.

Sample Input and Output

Input Sample #1

1 8
CPZNCCP
4
1 1 1 8
1 3 1 5
1 8 1 4
1 2 1 3

Output Sample #1

4
2
3
1

Input Sample #2

3 3
PP
PP
PP
CCC
CCC
3
1 1 3 3
3 3 2 2
1 1 1 3

Output Sample #2

2
2
1

Input Sample #3

4 4
CCC
CPC
PPP
CNP
ZZZZ
PPPP
CPZC
4
3 1 2 3
1 1 4 4
2 2 3 3
1 4 4 1

Output Sample #3

1
2
1
3

Notes

Sample Explanation #3

As illustrated in the figure:

  • For the first query, only blue doors need to be passed through.
  • For the second query, both blue and green doors need to be passed through.
  • For the third query, only blue doors need to be passed through.
  • For the fourth query, the path includes red, blue, and green doors.

Data Range

For $100\%$ of the data, $1 \leq n, m, q \leq 100$, $nm > 1$, $1 \leq a_i, c_i \leq n$, $1 \leq b_i, d_i \leq m$, $(a_i, b_i) \neq (c_i, d_i)$, and the character matrices only contain the characters P, C, Z, and N.

This problem uses subtask testing.

Subtask Special Condition Points
1 $n = 1$ 11
2 The first character matrix contains only P, the second only C 13
3 All character matrices contain only C and P 24
4 No special conditions 22

Notes

This problem's score is set according to the original COCI contest, with a maximum of 70 points.

The problem is translated from COCI2022-2023 CONTEST #1 T2 Labyrinth.

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
1 8 CPZNCCP 4 1 1 1 8 1 3 1 5 1 8 1 4 1 2 1 3
样例输出
4 2 3 1