Wednesday, 11 June 2014

nr. 946 - Radar

This is the first part of the (mini) series that will show the tricks of Radar puzzle type.
Let's see the first trick.

If the first and second clue is same on any side, than the first and second row is totally same.
The same is true, if there is 0 among the clues. And its neighbour and its second neighbour is same.

This is a simple consequence of the rule that every rectangles is at least 2 cells width.
So if there is a shaded cell in first row it will continue in the second. And the two clues are same, so there is no more shaded cells in the second row.

Here is an example which use only this trick.
For instance if R3C1 is shaded then it is trivial that R3C2 is shaded too.
Because of the trick the inverse is also true.
If R3C2 is shaded then R3C1 is shaded too. 
This is not trivial, but it is not a too difficult consequnce.

Another example is that if R3C2 is empty then it is trivial that R3C1 is empty too.
But the inverse is also true.
If R3C1 is empty then R3C2 is empty too.

First I check both sides of the clue and mark this pattern to not forget to use this trick.
In this puzzle there are 4 places where 1st and 2nd clue are same. But R6 and R7 won't give any extra informations because of the zeros.
Next time I will show the first steps of this puzzle. 


  1. The clues for rows 3 and 4 seem to be switched.

    Also, really looking forward to the rest of the series, thanks!

  2. Thanks. i recognized the mistake, but it seems I forgot to reexport the image. Sorry.