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Definitions of terminology

 
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Androgicus



Joined: 10 Apr 2006
Posts: 2
Location: Sunshine

PostPosted: Mon Apr 10, 2006 4:02 am    Post subject: Definitions of terminology Reply with quote

Can someone please give me a solid explantation of the phrases:
Mandatory Pairs,
Candidate Profiles,
Mutual Reception.
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David Bryant



Joined: 29 Jul 2005
Posts: 559
Location: Denver, Colorado

PostPosted: Mon Apr 10, 2006 11:11 pm    Post subject: Candidate Lists Reply with quote

I'm not sure I can explain mandatory pairs, or mutual reception. But I can define candidate lists.

The candidate list for a particular unresolved cell is the set of values that might possibly be placed in that cell without violating the rules of sudoku.

The initial candidate list for an unresolved cell is formed by removing all values already entered in the row, column, and 3x3 box containing that cell from the complete set of symbols {1, 2, 3, ..., 9}.

For example, if r1c1 is unresolved and row 1 contains {1, 2, 3}, column 1 contains {4, 5}, and the top left 3x3 box contains {6, 7}, then the initial candidate list for r1c1 is just {8, 9}.

Most people have to write some candidate lists down while working on a sudoku, especially if it's a tough one. Progress is often made by finding some way to eliminate one or more digits from the initial candidate list for a particular cell.

In general there are only two ways to place the right value in an unresolved cell.

-- If the candidate list can be reduced to a single value, that digit must go in this cell ("sole candidate").

-- If this cell is the only one in a row/column/box containing a particular candidate, then that digit must go in this cell ("unique in row/column/box").

Ask Alan R about the other terms. dcb Smile
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Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA