What is a hidden pair in Sudoku?
What is a hidden pair in Sudoku?
A hidden pair occurs when a pair of numbers appears in exactly two squares in a row, column, or block, but those two numbers aren’t the only ones in their squares. In the above example, the 5 and 9 in red are a hidden pair. Aug 15, 2021
How can you tell a swordfish in Sudoku?
A Swordfish is a 3 by 3 nine-cell pattern where a candidate is found on three different rows (or three columns) and they line up in the opposite direction. Eventually we will fix three candidates somewhere in those cells which excludes all other candidates in those units. Apr 11, 2008
What is the knight’s move in Sudoku?
Knight’s move sudoku This path forms an ‘L’ shape as shown below. When you take into account all the other possible cells within a ‘knight’s move’ of the center cell, it means that in a knight’s move chess sudoku, whatever number appears in the blue center cell below, cannot appear in any of the yellow cells.
Where are the hidden quads in Sudoku?
The Hidden Quad is {1,4,6,9} in Box 5 and exists only in the four cells [D4,D6,F4,F6]. Therefore other candidates (red text on yellow background) can be removed. This very special puzzle also produces a perfectly formed Empty Rectangle later on. Apr 9, 2008
What is the one rule in Sudoku?
Sudoku Rule № 1: Use Numbers 1-9Within the rows and columns are 9 “squares” (made up of 3 x 3 spaces). Each row, column and square (9 spaces each) needs to be filled out with the numbers 1-9, without repeating any numbers within the row, column or square. Does it sound complicated?
What is the most difficult puzzle in the world?
World’s Most Difficult Jigsaw Puzzle: Dalmatians.
Can you solve Sudoku with matrices?
Sudoku puzzles of large size also require other algorithms that are more involved on different qualities of a Sudoku puzzle. Permutation matrices can be used to solve those larger puzzles with the help of computer formatting. May 13, 2020
