Description
# Homework3: Sudoku
## Introduction
In this homework, you will need to design a sudoku solver that can automatically solve the sudoku puzzle within reasonable time constraint.<br>
A sudoku puzzle is represented by a 9×9 matrix with some missing elements in it. Each element in the matrix is an integer value from 1 to 9.
“`
For example:
columns
+—–+ +—–+ +—–+
9,5,7,6,1,3,2,8,4 |9,5,7| |6,1,3| |2,8,4|
4,8,3,2,5,7,1,9,6 |4,8,3| |2,5,7| |1,9,6|
r 6,1,2,8,4,9,5,3,7 |6,1,2| |8,4,9| |5,3,7|
o 1,7,8,3,6,4,9,5,2 ——-> +—–+ +—–+ +—–+
w 5,2,4,9,7,1,3,6,8 ——-> block0 block1 block2
s 3,6,9,5,2,8,7,4,1
8,4,5,7,9,2,6,1,3 +—–+ +—–+ +—–+
2,9,1,4,3,6,8,7,5 |1,7,8| |3,6,4| |9,5,2|
7,3,6,1,8,5,4,2,9 |5,2,4| |9,7,1| |3,6,8|
|3,6,9| |5,2,8| |7,4,1|
+—–+ +—–+ +—–+
block3 block4 block5
+—–+ +—–+ +—–+
|8,4,5| |7,9,2| |6,1,3|
|2,9,1| |4,3,6| |8,7,5|
|7,3,6| |1,8,5| |4,2,9|
+—–+ +—–+ +—–+
block6 block7 block8
“`
A solved sudoku puzzle should satisfy following requirements:
1. Each row consists of a sequence of numbers from 1 to 9 ,and each digit can only occurs once
2. Each col consists of a sequence of numbers from 1 to 9 ,and each digit can only occurs once
3. Each block consists of a sequence of numbers from 1 to 9 ,and each digit can only occurs once
## Requirements
Given the template code provided by TA, you need to fulfill all the methods and functions in the code. The score/point for each method or function is explained in the docstring.
#### MUST READ
+ You cannot use any third-party package such as numpy, pandas, and etc.
+ You can only use python primitive types and statements to solve the problem.
+ Do not copy others code. (0 scores for punishment)
## Expected Execution Result
### __ init __
“`python
# Content in sudoku2.txt
# ======================
# 0,5,7,6,1,3,2,8,4
# 4,8,3,2,5,0,0,0,6
# 6,1,2,8,4,0,5,0,7
# 1,7,8,3,0,0,0,0,2
# 5,2,4,9,7,1,3,6,8
# 3,6,0,0,0,0,7,4,1
# 8,4,5,7,9,2,6,1,3
# 2,9,1,4,3,6,8,7,5
# 7,3,6,1,8,0,0,0,0
# Test constructor
sudoku1=Sudoku(“sudoku2.txt”)
“`
### __ str __
“`python
# Test __str__ magic method
print(sudoku1, end=”\n\n”)
“`
0 5 7 6 1 3 2 8 4<br>
4 8 3 2 5 0 0 0 6<br>
6 1 2 8 4 0 5 0 7<br>
1 7 8 3 0 0 0 0 2<br>
5 2 4 9 7 1 3 6 8<br>
3 6 0 0 0 0 7 4 1<br>
8 4 5 7 9 2 6 1 3<br>
2 9 1 4 3 6 8 7 5<br>
7 3 6 1 8 0 0 0 0
### check_block
“`python
# Test check_block
print(sudoku1.check_block(0))
print(sudoku1.check_block(3))
print(sudoku1.check_block(6))
“`
True<br>
True<br>
True
### check_row
“`python
# Test check_row
print(sudoku1.check_row(0))
print(sudoku1.check_row(1))
print(sudoku1.check_row(2))
“`
True<br>
True<br>
True
### check_col
“`python
# Test check_col
print(sudoku1.check_col(0))
print(sudoku1.check_col(1))
print(sudoku1.check_col(2))
“`
True<br>
True<br>
True
### is_solved
“`python
#Test is_solved
print(sudoku1.is_solved())
“`
False
### solve
“`python
# Test solve
sudoku1.solve()
print(sudoku1, end=”\n\n”)
“`
9 5 7 6 1 3 2 8 4<br>
4 8 3 2 5 1 9 6 6<br>
6 1 2 8 4 9 5 3 7<br>
1 7 8 3 6 4 9 5 2<br>
5 2 4 9 7 1 3 6 8<br>
3 6 9 5 2 8 7 4 1<br>
8 4 5 7 9 2 6 1 3<br>
2 9 1 4 3 6 8 7 5<br>
7 3 6 1 8 5 4 2 9
### is_solved after solve
“`python
#Test is_solved
print(sudoku1.is_solved())
“`
True
