Fixed a bug in solve2

main.py

@@ -1,6 +1,9 @@
 #!/usr/bin/env python3
 
+"This module does something"
+
 from itertools import combinations_with_replacement
+import sys
 
 
 def solve1(width, pattern):
@@ -67,8 +70,10 @@ def solve2(width, pattern, constraints=None):
     maxgap = width - sum(pattern[1:]) - (len(pattern) - 1) - p
 
     for gap in range(maxgap + 1):
-        e = expand_solution((gap,), gap + p + 1, (p,))
+        # constraint width
-        if not matches(e, constraints[:gap + p + 1]):
+        cw = (gap + p + 1) if len(pattern) > 1 else width
+        e = expand_solution((gap,), cw, (p,))
+        if not matches(e, constraints[:cw]):
             continue
         if len(pattern) == 1:
             yield (gap,)
@@ -79,12 +84,79 @@ def solve2(width, pattern, constraints=None):
         for s in solve2(subwidth, subpattern, subconstraints):
             yield (gap, s[0]+1) + s[1:]
 
+def invariants(width, pattern, constraints=None):
+    "compute invariants"
+    invs = []
+    for sol in solve2(width, pattern, constraints):
+        exp = list(expand_solution(sol, width, pattern))
+        count += 1
+        if len(invs) == 0:
+            invs = exp
+        else:
+            for i, e in enumerate(exp):
+                if invs[i] != e:
+                    invs[i] = -1
+    return count, invs
+
+def visual(constraints):
+    "returns a visual representation of constraints"
+    return "".join({1:'\N{LEFT SEVEN EIGHTHS BLOCK}', 0:'.', -1:'?'}[x] for x in constraints)
+
+class Board:
+    """Board
+
+    A board is actually a list of constraints.
+    A cell with 1 or 0 is fixed. A cell with -1
+    doesn't have a known value yet.
+    """
+
+    def __init__(self, patterns):
+        self.col_patterns = patterns[0]
+        self.row_patterns = patterns[1]
+        self.width = len(patterns[0])
+        self.height = len(patterns[1])
+        self.rows = [None] * self.height
+        for i in range(self.height):
+            self.rows[i] = [-1] * self.width
+
+        print("rows:")
+        for y in range(self.height):
+            n, c = invariants(self.width, self.row_patterns[y])
+            print(n, self.row_patterns[y], visual(c))
+
+        print("cols:")
+        for x in range(self.height):
+            n, c = invariants(self.width, self.col_patterns[x])
+            print(n, self.col_patterns[x], visual(c))
+
+        print(self.row(0))
+
+    def col(self, i):
+        """a column"""
+        return [self.rows[x][i] for x in range(self.height)]
+
+    def row(self, i):
+        """a row"""
+        return self.rows[i]
+
+    def solve(self):
+        min_row_index = 0
+        min_row_count = 0
+        for y in range(self.height):
+            count = 0
+            for sol in solve2(self.width, self.row_patterns[y], self.row(y)):
+                count += 1
+            if count < min_row_count:
+                min_row_count = count
+                min_row_index = y
+
+
+        pass
 
 if __name__ == "__main__":
 
-    import sys
-
     def draw(solution, width, pattern):
+        "draws a solution"
         for s, p in zip(solution, pattern):
             print('.' * s, end="")
             print('\N{LEFT SEVEN EIGHTHS BLOCK}' * p, end="")
@@ -104,16 +176,24 @@ if __name__ == "__main__":
     #     if matches(e, constraints):
     #         draw(solution, width, pattern)
 
-    fixed = []
+    def parse(rows):
-    for sol in solve2(width, pattern, constraints):
+        "parses '1 1, 1 2 3' into [[1, 1], [1, 2, 3]]"
-        exp = list(expand_solution(sol, width, pattern))
+        rows = rows.split(",")
-        if len(fixed) == 0:
+        rows = [[int(y) for y in x.strip().split()] for x in rows]
-            fixed = exp
+        return rows
-        else:
+
-            for i,e in enumerate(exp):
+
-                if fixed[i] != e:
+    b = Board((
-                    fixed[i] = -1
+        parse("""1 1 1 1 1, 1 1 1, 1 1 1 1, 1 2, 1 1 1 1, 1 1 1, 1 1 1,
-        draw(sol, width, pattern)
+                 3 1, 1 1, 1 2 6 1, 2 1, 2 3 1, 1 1, 1 1 3 1, 2 1 1"""),
+        parse("""1 2, 1 1 2, 2 1 1 1 1, 3 1, 1 1 1 1, 1 2 1, 1, 1 1 1 2,
+                 2 2 1 1, 1 1 1 1 1, 1 2 2, 2 2, 1 1 1 1 1, 1 1 1 1, 1 1""")
+    ))
+
+    # c = Board((
+    #     parse("""1 5 2, 1 1 2, 1 1 2 1 2, 2 2, 2 1 1 1, 1 1 1, 1 1, 1 1 1, 2 3 1 1,
+    #              1 2 3 1 1, 1 3 1 1, 2 1 1 1, 1 1 1 2 1, 1 1 1 2 1, 2 1"""),
+    #     parse("""1 2 1 1, 1 1 4, 2 1, 1 1 1 1 2, 1 3 1 1, 1 2, 1 1 1 1 1 1,
+    #              1 1 1 1 1 2, 1 1 2, 1 2 1 1, 3 1 4, 1 4 1, 3, 3 1 1, 1 2 1""")
+    # ))
 
-    print("invariants:")
-    print("".join({1:'\N{LEFT SEVEN EIGHTHS BLOCK}',0:'.',-1:'?'}[x] for x in fixed))