Rules: Fill in the grid with 1, 2, 3, 4, 5, 6, 7, 8, and 9 so that each row, column, and 3x3 block has no repeated entries, AND so that each pair of orthogonally adjacent cells obeys the "greater than" (>) or "less than" (<) symbol between the cells. For example, the second cell in the first row (above the "3") is less than the cell to its left, but more than the cell to its right, and more than the cell below it (i.e. more than 3).
Ed Pegg's wonderful article Sudoku Variations has an example of a "Greater Than" Sudoku puzzle from Puzzler Magazine in which NO initial conditions are given; in that example the greater/less relationships alone are enough to uniquely determine the puzzle. This of course shows that the minimum number of clues necessary to ensure a unique solution to a "Greater Than" Sudoku puzzle is zero! How many such no-clue "Greater Than" Sudoku puzzles are there?
Solutions are due by noon on Tuesday, April 11, 2006.
Return solutions ON PAPER to Laura Taalman, Burruss 127, MSC 7803.
Include your name and email address with your solution.