September 2017 Update

Task/Solve-a-Numbrix-puzzle/Python/solve-a-numbrix-puzzle.py

@@ -0,0 +1,98 @@
+from sys import stdout
+neighbours = [[-1, 0], [0, -1], [1, 0], [0, 1]]
+exists = []
+lastNumber = 0
+wid = 0
+hei = 0
+
+
+def find_next(pa, x, y, z):
+    for i in range(4):
+        a = x + neighbours[i][0]
+        b = y + neighbours[i][1]
+        if wid > a > -1 and hei > b > -1:
+            if pa[a][b] == z:
+                return a, b
+
+    return -1, -1
+
+
+def find_solution(pa, x, y, z):
+    if z > lastNumber:
+        return 1
+    if exists[z] == 1:
+        s = find_next(pa, x, y, z)
+        if s[0] < 0:
+            return 0
+        return find_solution(pa, s[0], s[1], z + 1)
+
+    for i in range(4):
+        a = x + neighbours[i][0]
+        b = y + neighbours[i][1]
+        if wid > a > -1 and hei > b > -1:
+            if pa[a][b] == 0:
+                pa[a][b] = z
+                r = find_solution(pa, a, b, z + 1)
+                if r == 1:
+                    return 1
+                pa[a][b] = 0
+
+    return 0
+
+
+def solve(pz, w, h):
+    global lastNumber, wid, hei, exists
+
+    lastNumber = w * h
+    wid = w
+    hei = h
+    exists = [0 for j in range(lastNumber + 1)]
+
+    pa = [[0 for j in range(h)] for i in range(w)]
+    st = pz.split()
+    idx = 0
+    for j in range(h):
+        for i in range(w):
+            if st[idx] == ".":
+                idx += 1
+            else:
+                pa[i][j] = int(st[idx])
+                exists[pa[i][j]] = 1
+                idx += 1
+
+    x = 0
+    y = 0
+    t = w * h + 1
+    for j in range(h):
+        for i in range(w):
+            if pa[i][j] != 0 and pa[i][j] < t:
+                t = pa[i][j]
+                x = i
+                y = j
+
+    return find_solution(pa, x, y, t + 1), pa
+
+
+def show_result(r):
+    if r[0] == 1:
+        for j in range(hei):
+            for i in range(wid):
+                stdout.write(" {:0{}d}".format(r[1][i][j], 2))
+            print()
+    else:
+        stdout.write("No Solution!\n")
+
+    print()
+
+
+r = solve(". . . . . . . . . . . 46 45 . 55 74 . . . 38 . . 43 . . 78 . . 35 . . . . . 71 . . . 33 . . . 59 . . . 17"
+          " . . . . . 67 . . 18 . . 11 . . 64 . . . 24 21 . 1  2 . . . . . . . . . . .", 9, 9)
+show_result(r)
+
+r = solve(". . . . . . . . . . 11 12 15 18 21 62 61 . .  6 . . . . . 60 . . 33 . . . . . 57 . . 32 . . . . . 56 . . 37"
+          " .  1 . . . 73 . . 38 . . . . . 72 . . 43 44 47 48 51 76 77 . . . . . . . . . .", 9, 9)
+show_result(r)
+
+r = solve("17 . . . 11 . . . 59 . 15 . . 6 . . 61 . . . 3 . . .  63 . . . . . . 66 . . . . 23 24 . 68 67 78 . 54 55"
+          " . . . . 72 . . . . . . 35 . . . 49 . . . 29 . . 40 . . 47 . 31 . . . 39 . . . 45", 9, 9)
+show_result(r)