Implement mutation operator

src/genetic_algorithm.py

@@ -1,5 +1,5 @@
 from numpy import sum, append, arange, delete, where
-from numpy.random import randint, choice, shuffle
+from numpy.random import randint, choice, shuffle, random
 from pandas import DataFrame
 
 
@@ -115,6 +115,18 @@ def crossover(mode, parents, m):
     return position_crossover(parents, m)
 
 
+def mutate(solution, n, probability=0.001):
+    if random() > probability:
+        return solution
+    row = solution.sample()
+    random_element = randint(n)
+    while element_in_dataframe(solution=solution, element=random_element):
+        random_element = randint(n)
+    solution["point"].iloc[row.index] = random_element
+    solution["distance"].loc[row.index] = 0
+    return solution
+
+
 def element_in_dataframe(solution, element):
     duplicates = solution.query(f"point == {element}")
     return not duplicates.empty