Pollard’s rho algorithm for computing dicrete logarithms

Here is an implementation in python of
Pollard’s rho method for computing the discrete logarithm. Continue reading “Pollard’s rho algorithm for computing dicrete logarithms” »

Sudoku Solver in Python with Recursion – Maybe a Solution

Continue from here.

I managed to find a solution which worked for 2 puzzles I checked. I am sure it will not work always, but I like the solution. It is clear and without much code.

I find all the possible numbers that can be inserted in each cell.
If the cell has only one candidate then we should insert it and call the solve function again.
If all cells are filled then the program must stops.
I think I will have a problem in case of I could not find a cell with one only candidate…Then the program won’t stop,
but who cares? The program is just for learning purposes.

Here is the code:
Continue reading “Sudoku Solver in Python with Recursion – Maybe a Solution” »

Sudoku Solver in Python part 3

Previous post here

I continued my try to solve Sudoku with Python. Actually I have never solve a Sudoku puzzle myself

Here is the updated code
Continue reading “Sudoku Solver in Python part 3” »

Sudoku solver with python part 2

Continue from here.

Because of the beach and the sun I have only the following code:

 python | 
  |
?
 
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# -*- coding: utf-8 -*-
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"""
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Created on Wed Aug 11 18:21:28 2011
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@author: gkomninos
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"""
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class Position(object):
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    '''A Sudoku cell '''
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    def __init__(self, row, column, value='x', fixed = False):
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        '''Constructor like'''
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        self.Row = row
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        self.Column = column
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        self.Box = None
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        self.Value = value
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        self.Fixed = fixed
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    def __calc_box(self):
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        '''calculates in which "box" the cell belongs'''
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        if( self.Row >= 0 and self.Row < = 2 and 
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            self.Column >= 0 and self.Column < = 2):
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            return 0
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        elif( self.Row >= 0 and self.Row < = 2 and
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              self.Column >= 3 and self.Column < =5):
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            return 1
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        return 0
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    def to_string(self):
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        '''returns the value of a Position object'''
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        return self.Value
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    def swap(self, other_object):
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        '''Swaps two cells'''
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        if(self.Fixed == True or other_object.Fixed == True):
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            return False
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        tmp_row = self.Row
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        tmp_column = self.Column
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        tmp_box = self.Box
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        tmp_value = self.Value
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        self.Row = other_object.Row
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        self.Column = other_object.Column
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        self.Box = other_object.Box
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        self.Value = other_object.Value
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        other_object.Row = tmp_row
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        other_object.Column = tmp_column
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        other_object.Box = tmp_box
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        other_object.Value = tmp_value
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        return True
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    if __name__ == "__main__":
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        print 'Position object'

Attempt to create a Sudoku solver in python

I will try to make a Sudoku solver in python as a summer project. Hope to finish it.
I will not explain the rules here. You can check them in wikipedia’s article for sudoku or summarized here.

First I must find a way to represent Sudokus in python. I am thinking to store each puzzle in a file formatted like:

5 3 x x 7 x x x x
6 x x 1 9 5 x x x
x 9 8 x x x x 6 x
8 x x x 6 x x x 3
4 x x 8 x 3 x x 1
7 x x x 2 x x x 6
x 6 x x x x 2 8 x
x x x 4 1 9 x x 5
x x x x 8 x x 7 9
Continue reading “Attempt to create a Sudoku solver in python” »

Web programming with Web.py

web.py is a simple python framework for developing.
I started searching for a python web framework an stumbled upon web.py.
I have a little experience with django and i found it pretty good. What i didn’t like about django was that it has
a relatively big learning curve and it hides you some details ( makes things look magic ).

I want something simple with a high level of customization without too much effort.

I have read the tutorial from web.py and i in a few hours understood how it works .
I have implemented a simple demo project for testing.
Continue reading “Web programming with Web.py” »

Simple python script for mysql backups

Here is a small script i wrote in python for making quick backups and restores for mysql dbms.
It’s very simple with a few minor bugs.
Continue reading “Simple python script for mysql backups” »