Sudoku Night Cafe 與 Sudoku 5000 使用情況與統計

Sudoku originally called Number Place, is a logic-based, combinatorial number-placement puzzle. The objective is to fill a 9x9 grid with digits so that each column, each row, and each of the nine 3?3 sub-grids that compose the grid (also called "boxes", "blocks", "regions", or "sub- squares") contains all of the digits from 1 to 9. The puzzle setter provides a partially completed grid, which has a unique solution. There are 5 levels of difficulty. Each category contains 1,000 tasks. Total 5000 puzzles !