Merge pull request #86 from stonebig/master

sudoku precision and ortools version

Author: stonebig

docs/Solvers_Raymond_Hettinger/python/sudoku_norvig_for_comparison_of_complexity.py

@@ -189,8 +189,12 @@ def random_puzzle(N=17):
 
 grid1  = '003020600900305001001806400008102900700000008006708200002609500800203009005010300'
 grid2  = '4.....8.5.3..........7......2.....6.....8.4......1.......6.3.7.5..2.....1.4......'
-hard1  = '.....6....59.....82....8....45........3........6..3.54...325..6..................'
-hard2  = '8..........36......7..9.2...5...7.......457.....1...3...1....68..85...1..9....4..'    
+hard00 = '.......1......2..3...4...........5..4.16.......71......5....2......8..4..3.91....'
+hard0  = '........1.......23..4..5......1.........3.6....7...58.....67....1...4...52.......' #is a sudoku 17 digits, https://en.wikipedia.org/wiki/Mathematics_of_Sudoku
+hard1  = '.....6....59.....82....8....45........3........6..3.54...325..6..................' #aargh, not a sudoku !, https://www.thonky.com/sudoku/solution-count
+hard2  = '8..........36......7..9.2...5...7.......457.....1...3...1....68..85...1..9....4..'
+medi1  = '.6..5..2....3...9.7..6...1...6.3.4....4.7.1....5.9.8...4...1..6.3...8....2..4..5.'
+medi2  = '.2..........6....3.74.8.........3..2.8..4..1.6..5.........1.78.5....9..........4.'  
 if __name__ == '__main__':
     test()
     solve_all([hard1], "easy", 0)

docs/Solvers_Raymond_Hettinger/python/sudoku_ortools.py

@@ -0,0 +1,104 @@
+#!/usr/bin/env python3
+# Copyright 2010-2022 Google LLC
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""This model implements a sudoku solver."""
+
+from ortools.sat.python import cp_model
+
+
+def solve_sudoku():
+    """Solves the sudoku problem with the CP-SAT solver."""
+    # Create the model.
+    model = cp_model.CpModel()
+
+    cell_size = 3
+    line_size = cell_size**2
+    line = list(range(0, line_size))
+    cell = list(range(0, cell_size))
+
+    initial_grid = [
+        [0, 0, 0, 0, 0, 0, 0, 0, 1],
+        [0, 0, 0, 0, 0, 0, 0, 2, 3],
+        [0, 0, 4, 0, 0, 5, 0, 0, 0],
+        [0, 0, 0, 1, 0, 0, 0, 0, 0],
+        [0, 0, 0, 0, 3, 0, 6, 0, 0],
+        [0, 0, 7, 0, 0, 0, 5, 8, 0],
+        [0, 0, 0, 0, 6, 7, 0, 0, 6],
+        [0, 1, 0, 0, 0, 4, 0, 0, 0],
+        [5, 2, 0, 0, 0, 0, 0, 0, 0],
+    ]
+
+    hard1  = [
+[0, 0, 0, 0, 0, 6, 0, 0, 0],
+[0, 5, 9, 0, 0, 0, 0, 0, 8],
+[2, 0, 0, 0, 0, 8, 0, 0, 0],
+[0, 4, 5, 0, 0, 0, 0, 0, 0],
+[0, 0, 3, 0, 0, 0, 0, 0, 0],
+[0, 0, 6, 0, 0, 3, 0, 5, 4],
+[0, 0, 0, 3, 2, 5, 0, 0, 6],
+[0, 0, 0, 0, 0, 0, 0, 0, 0],
+[0, 0, 0, 0, 0, 0, 0, 0, 0],
+]
+    hard0  = [
+        [0, 0, 0, 0, 0, 0, 0, 0, 1],
+        [0, 0, 0, 0, 0, 0, 0, 2, 3],
+        [0, 0, 4, 0, 0, 5, 0, 0, 0],
+        [0, 0, 0, 1, 0, 0, 0, 0, 0],
+        [0, 0, 0, 0, 3, 0, 6, 0, 0],
+        [0, 0, 7, 0, 0, 0, 5, 8, 0],
+        [0, 0, 0, 0, 6, 7, 0, 0, 0],
+        [0, 1, 0, 0, 0, 4, 0, 0, 0],
+        [5, 2, 0, 0, 0, 0, 0, 0, 0],
+]
+    
+    initial_grid = hard0
+
+    grid = {}
+    for i in line:
+        for j in line:
+            grid[(i, j)] = model.NewIntVar(1, line_size, "grid %i %i" % (i, j))
+
+    # AllDifferent on rows.
+    for i in line:
+        model.AddAllDifferent(grid[(i, j)] for j in line)
+
+    # AllDifferent on columns.
+    for j in line:
+        model.AddAllDifferent(grid[(i, j)] for i in line)
+
+    # AllDifferent on cells.
+    for i in cell:
+        for j in cell:
+            one_cell = []
+            for di in cell:
+                for dj in cell:
+                    one_cell.append(grid[(i * cell_size + di, j * cell_size + dj)])
+
+            model.AddAllDifferent(one_cell)
+
+    # Initial values.
+    for i in line:
+        for j in line:
+            if initial_grid[i][j]:
+                model.Add(grid[(i, j)] == initial_grid[i][j])
+
+    # Solve and print out the solution.
+    solver = cp_model.CpSolver()
+    status = solver.Solve(model)
+    if status == cp_model.OPTIMAL:
+        for i in line:
+            print([int(solver.Value(grid[(i, j)])) for j in line])
+
+
+solve_sudoku()