Solve problem 111 and fix bug in lib prime.

python/e111.py

@@ -0,0 +1,46 @@
+from lib_prime import is_prime_rabin_miller as is_prime
+
+
+def get_permutations(number: str, number_permutations: int, start_index = 0):
+    """ Returns number permutated at number_permutations locations. """
+    if number_permutations == 0:
+        yield int(number)
+    else:
+        numbers = list("0123456789")
+        base = list(str(number))
+        for i in range(start_index, len(base)):
+            digit_stored = base[i]
+            for n in numbers:
+                if n == digit_stored:
+                    continue
+                base[i] = n
+                if base[0] == "0":
+                    continue
+                for p in get_permutations("".join(base), number_permutations - 1, i):
+                    yield p
+            base[i] = digit_stored
+
+
+def euler_111():
+    result = 0
+    n = 10
+    for d in range(10):
+        subresult = 0
+        base = "".join([str(d) for _ in range(n)])
+        for p in get_permutations(base, 1):
+            if is_prime(p):
+                subresult += p
+        if subresult == 0:
+            # d in [0, 2, 8] requires two permutations to yield at least one prime
+            for p in get_permutations(base, 2):
+                if is_prime(p):
+                    subresult += p
+        assert subresult > 0, "More than to permutations required to yield prime"
+        result += subresult
+    return result
+
+
+if __name__ == "__main__":
+    solution = euler_111()
+    print("e111.py: " + str(solution))
+    assert(solution == 612407567715)