Data commit

Task/Nonogram-solver/Python/nonogram-solver-1.py

@@ -0,0 +1,119 @@
+from itertools import izip
+
+def gen_row(w, s):
+    """Create all patterns of a row or col that match given runs."""
+    def gen_seg(o, sp):
+        if not o:
+            return [[2] * sp]
+        return [[2] * x + o[0] + tail
+                for x in xrange(1, sp - len(o) + 2)
+                for tail in gen_seg(o[1:], sp - x)]
+
+    return [x[1:] for x in gen_seg([[1] * i for i in s], w + 1 - sum(s))]
+
+
+def deduce(hr, vr):
+    """Fix inevitable value of cells, and propagate."""
+    def allowable(row):
+        return reduce(lambda a, b: [x | y for x, y in izip(a, b)], row)
+
+    def fits(a, b):
+        return all(x & y for x, y in izip(a, b))
+
+    def fix_col(n):
+        """See if any value in a given column is fixed;
+        if so, mark its corresponding row for future fixup."""
+        c = [x[n] for x in can_do]
+        cols[n] = [x for x in cols[n] if fits(x, c)]
+        for i, x in enumerate(allowable(cols[n])):
+            if x != can_do[i][n]:
+                mod_rows.add(i)
+                can_do[i][n] &= x
+
+    def fix_row(n):
+        """Ditto, for rows."""
+        c = can_do[n]
+        rows[n] = [x for x in rows[n] if fits(x, c)]
+        for i, x in enumerate(allowable(rows[n])):
+            if x != can_do[n][i]:
+                mod_cols.add(i)
+                can_do[n][i] &= x
+
+    def show_gram(m):
+        # If there's 'x', something is wrong.
+        # If there's '?', needs more work.
+        for x in m:
+            print " ".join("x#.?"[i] for i in x)
+        print
+
+    w, h = len(vr), len(hr)
+    rows = [gen_row(w, x) for x in hr]
+    cols = [gen_row(h, x) for x in vr]
+    can_do = map(allowable, rows)
+
+    # Initially mark all columns for update.
+    mod_rows, mod_cols = set(), set(xrange(w))
+
+    while mod_cols:
+        for i in mod_cols:
+            fix_col(i)
+        mod_cols = set()
+        for i in mod_rows:
+            fix_row(i)
+        mod_rows = set()
+
+    if all(can_do[i][j] in (1, 2) for j in xrange(w) for i in xrange(h)):
+        print "Solution would be unique" # but could be incorrect!
+    else:
+        print "Solution may not be unique, doing exhaustive search:"
+
+    # We actually do exhaustive search anyway. Unique solution takes
+    # no time in this phase anyway, but just in case there's no
+    # solution (could happen?).
+    out = [0] * h
+
+    def try_all(n = 0):
+        if n >= h:
+            for j in xrange(w):
+                if [x[j] for x in out] not in cols[j]:
+                    return 0
+            show_gram(out)
+            return 1
+        sol = 0
+        for x in rows[n]:
+            out[n] = x
+            sol += try_all(n + 1)
+        return sol
+
+    n = try_all()
+    if not n:
+        print "No solution."
+    elif n == 1:
+        print "Unique solution."
+    else:
+        print n, "solutions."
+    print
+
+
+def solve(p, show_runs=True):
+    s = [[[ord(c) - ord('A') + 1 for c in w] for w in l.split()]
+         for l in p.splitlines()]
+    if show_runs:
+        print "Horizontal runs:", s[0]
+        print "Vertical runs:", s[1]
+    deduce(s[0], s[1])
+
+
+def main():
+    # Read problems from file.
+    fn = "nonogram_problems.txt"
+    for p in (x for x in open(fn).read().split("\n\n") if x):
+        solve(p)
+
+    print "Extra example not solvable by deduction alone:"
+    solve("B B A A\nB B A A")
+
+    print "Extra example where there is no solution:"
+    solve("B A A\nA A A")
+
+main()

Task/Nonogram-solver/Python/nonogram-solver-2.py

@@ -0,0 +1,104 @@
+from functools import reduce
+
+def gen_row(w, s):
+    """Create all patterns of a row or col that match given runs."""
+    def gen_seg(o, sp):
+        if not o:
+            return [[2] * sp]
+        return [[2] * x + o[0] + tail
+                for x in range(1, sp - len(o) + 2)
+                for tail in gen_seg(o[1:], sp - x)]
+
+    return [x[1:] for x in gen_seg([[1] * i for i in s], w + 1 - sum(s))]
+
+
+def deduce(hr, vr):
+    """Fix inevitable value of cells, and propagate."""
+    def allowable(row):
+        return reduce(lambda a, b: [x | y for x, y in zip(a, b)], row)
+
+    def fits(a, b):
+        return all(x & y for x, y in zip(a, b))
+
+    def fix_col(n):
+        """See if any value in a given column is fixed;
+        if so, mark its corresponding row for future fixup."""
+        c = [x[n] for x in can_do]
+        cols[n] = [x for x in cols[n] if fits(x, c)]
+        for i, x in enumerate(allowable(cols[n])):
+            if x != can_do[i][n]:
+                mod_rows.add(i)
+                can_do[i][n] &= x
+
+    def fix_row(n):
+        """Ditto, for rows."""
+        c = can_do[n]
+        rows[n] = [x for x in rows[n] if fits(x, c)]
+        for i, x in enumerate(allowable(rows[n])):
+            if x != can_do[n][i]:
+                mod_cols.add(i)
+                can_do[n][i] &= x
+
+    def show_gram(m):
+        # If there's 'x', something is wrong.
+        # If there's '?', needs more work.
+        for x in m:
+            print(" ".join("x#.?"[i] for i in x))
+        print()
+
+    w, h = len(vr), len(hr)
+    rows = [gen_row(w, x) for x in hr]
+    cols = [gen_row(h, x) for x in vr]
+    can_do = list(map(allowable, rows))
+
+    # Initially mark all columns for update.
+    mod_rows, mod_cols = set(), set(range(w))
+
+    while mod_cols:
+        for i in mod_cols:
+            fix_col(i)
+        mod_cols = set()
+        for i in mod_rows:
+            fix_row(i)
+        mod_rows = set()
+
+    if all(can_do[i][j] in (1, 2) for j in range(w) for i in range(h)):
+        print("Solution would be unique")  # but could be incorrect!
+    else:
+        print("Solution may not be unique, doing exhaustive search:")
+
+    # We actually do exhaustive search anyway. Unique solution takes
+    # no time in this phase anyway, but just in case there's no
+    # solution (could happen?).
+    out = [0] * h
+
+    def try_all(n = 0):
+        if n >= h:
+            for j in range(w):
+                if [x[j] for x in out] not in cols[j]:
+                    return 0
+            show_gram(out)
+            return 1
+        sol = 0
+        for x in rows[n]:
+            out[n] = x
+            sol += try_all(n + 1)
+        return sol
+
+    n = try_all()
+    if not n:
+        print("No solution.")
+    elif n == 1:
+        print("Unique solution.")
+    else:
+        print(n, "solutions.")
+    print()
+
+
+def solve(s, show_runs=True):
+    s = [[[ord(c) - ord('A') + 1 for c in w] for w in l.split()]
+         for l in p.splitlines()]
+    if show_runs:
+        print("Horizontal runs:", s[0])
+        print("Vertical runs:", s[1])
+    deduce(s[0], s[1])