Saturday, 23 May 2020

PUZZLE NO. 105 : Magic Square Sudoku



RULES : Classic sudoku rules apply. Shaded 3x3 squares are magic squares. The sum of the numbers in all rows, columns and two diagonals should be equal in a magic square.

8 comments:

  1. 6:10, it seems that the classic part was harder as compared to the variant part

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  2. 17:08. Was solving this variant for the first time. Was completely clueless for the first 5 minutes!

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    Replies
    1. If you know the properties of a magic square , it won't take you so long.

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  3. 7:24.Just when I thought that this was again going to be case of a difficult classic part, noticed a pair and also used uniqueness to solve the sudoku. Beautiful construction.

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    Replies
    1. Thanks kishore. A bit slow . I expected around 5 minutes from you.

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  4. For me magic part was more difficult compared to classic part. Hard one.

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    Replies
    1. Basically, if you are aware of the positions of the digits in a magic square , you will not find it very difficult..

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  5. You can do the magic square part first, without working anywhere else on the puzzle.

    Magic squares really are that restrictive. Applying both the magic squares and the sudoku restrictions, and switching when you get stuck will solve both squares.

    Non spoiler hint for those struggling with the squares.

    The numbers from 1-9 (which are all present in the square) sum to 45. Given this fact, which is easily verified, there is only one possible sum to share between all 3 rows, or all 3 columns. Figuring out this sum (or just googling 3x3 magic square) allows you to deduce enough further restrictions to solve the magic squares with the givens.

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Puzzle No. 462: XV Sudoku

  RULES: Place a digit from 1 to 9 in each empty cell so that each digit appears exactly once in each row, column and 3x3 outlined box. If t...