Su-doku is a Japanese game. No arithmetic is required to calculate. People of all ages can play Su-doku. It’s a type of brainteaser, placing numbers in squares, using simple rules of logic and deductions.
Rules for the game
1. It is a 9 × 9 square with few blank square whereas rest of them are filled.
2. We are to fill the blank squares with the numbers in such a way that every row, every column and every 3 × 3 box accommodates the digits 1–9 without repeating any.
3. The size of the game can be different for example 4 × 4, 16 × 16 etc. 4 × 4 puzzle and 16 × 16 puzzle must have numerals 1 to 4 and 1 to 16 respectively in each row column and sub-section.
Techniques
Though there are no specific methods to solve the game yet we will find some own made techniques.
Let us play this game with the following puzzles :
Solution
1. Scan the rows and columns.
2. In the top right corner of the above fig number 7 is required.
How we came to conclude that number 7 is required?
(a) We first analyzed its 3 × 3 square and came to
know that only 5 and 7 are required.
(b) If we put 5 in the top right box, it would conflict
as 5 is already in the top row. Here 7 is
appropriate.
(c) In the top right 3 × 3 region only one number
from 1 to 9 is missing and that is 5 which does
not conflict any row or column.
3. Now consider middle right 3 × 3 block. Here five numbers are missing but if we look at the rightmost column of the 9 × 9 grid we will find only 2 and 4 are missing.
(a) If we place 4 beneath 1 it would lead to a
conflict with the 4 already in the horizontal row.
(b) So placing 2 in this box makes no conflict.
Similarly one can fill the other blank boxes.
Here I am giving a few su-doku puzzles. You try yourself.
Q No. 1
Q No. 2
Q No. 3
Q No. 4
Q No. 5
Q No. 6
Q No. 7
Q. No. 8
Q. No. 9
Q. No. 10
Q. No. 11
Q. No. 12
Q. No. 13
Q. No. 14
Q. No. 15
Q. No. 16
Q. No. 17
Q. No. 18
Q. No. 19
Q. No. 20
Q. No. 21
Q. No. 22
Q. No. 23
Q. No. 24
Q. No. 25
