Impossible puzzle
RoboMWM opened this issue · comments
I haven't looked at it myself yet but @frostalf reported an issue with a sudoku game he was given.
The puzzle looks solvable to me. There might be a mistake in the upper middle block: at the current state of the puzzle the 1 and the 9 can be switched... These are not placeable jet and could be wrong.
@frostalf what exactly is the problem with the puzzle?
The problem with the puzzle revolves around the top portion and a horizontal portion. You can't place a 1 in the right corner because horizontally at the bottom right there is a 1 already. So once we place the 1 where it should go, top center kind of, next on that same line with the 1 but horizontal, we will place a 3 in the only spot in can go, towards the bottom. Next we will place the 6 next to the 3. This is where the problem arises. You also need to place an 8, but the only available line there is already an 8 vertically. If you tried to switch the 6 and the 8, there is also a 6 vertically. This makes the puzzle not solvable since the whole point of sudoku is to not have duplicate numbers going horizontal or vertically.
I couldn't really follow that, but I just sat down and solved it:
As I said in my last comment, the 9 and 1 that you placed in the middle column top row, cannot be placed with the info you have at that state. If you check my solution, they have to be switched.