ナンプレ忍者こえもん

"Sudoku Ninja Koemon" is a sudoku puzzle application developed based on the research of Japanese mathematicians.
The common way to solve Sudoku is to find a number that fits in a square, or conversely, find a square that contains a number. However, the Koemon method advocated by "Sudoku Ninja Koemon" does not search for numbers that fit in each square, but instead searches for numbers that do not fit in that square, and finally determines the number that fits in that square.
This app uses only proven techniques as mathematical theorems. There is no problem that cannot be solved without using temporary placement. All problems can be solved using math techniques.