PlaySudoku.us
Easy · Puzzle #172
2
7
3
6
1
4
8
3
2
5
4
2
1
7
9
5
9
3
1
2
4
6
9
4
9
1
3
8
2
2
7
4
1
9
7
3
1
6
2
4
1
4
9
8
7
The first Sudoku World Championship was held in Lucca, Italy, in 2006.
The first Sudoku World Championship was held in Lucca, Italy, in 2006.
Graph coloring and Sudoku are equivalent problems. Each cell is a node; edges connect cells that share a house. Solving Sudoku = coloring the graph with 9 colors.
Graph coloring and Sudoku are equivalent problems. Each cell is a node; edges connect cells that share a house. Solving Sudoku = coloring the graph with 9 colors.