# ------------------------------------------------------------
# Create a unique list from multiple lists containing duplicates
# ------------------------------------------------------------
# We define a function so the logic is reusable and clean.
def unique_from_lists(*lists):
"""
Accepts any number of lists and returns a single list
containing only unique values.
The algorithm:
- Use Python's built‑in 'set' type, which automatically
removes duplicates and provides O(1) average lookup time.
- Sets are ideal for deduplication because they are fast
and implemented in C.
- After merging all lists into a set, convert back to a list
to preserve a standard Python sequence type.
"""
# Create an empty set to accumulate unique values
unique_values = set()
# Iterate through all provided lists
for lst in lists:
# Update the set with the contents of each list
# 'update' efficiently adds all elements from the list
unique_values.update(lst)
# Convert the set back to a list
# Sorting is optional; here we sort for deterministic output
return sorted(unique_values)
# ------------------------------------------------------------
# Usage
# ------------------------------------------------------------
list_a = [1, 2, 3, 3, 3, 4, 6, 7, 8]
list_b = [3, 4, 5, 3, 5, 3, 6]
list_c = [6, 7, 8, 1]
result = unique_from_lists(list_a, list_b, list_c)
print(result)
'''
run:
[1, 2, 3, 4, 5, 6, 7, 8]
'''
