Set

Set (Data Structure)

Set is a collection of unique elements. It is an unordered, mutable, and indexed collection.

Operations

1. Add: Insert an element.
2. Remove: Remove an element.
3. Contains: Check if an element exists in the set.
4. Union: Combine two sets.
5. Intersection: Get common elements between two sets.
6. Difference: Get elements that are in one set but not in the other.

Example

# Create a set
s = {1, 2, 3}
 
# Add an element
s.add(4)
 
# Remove an element
s.remove(2)
 
# Check if an element exists
print(3 in s)  # True
 
# Union
s1 = {1, 2, 3}
s2 = {3, 4, 5}
print(s1.union(s2))  # {1, 2, 3, 4, 5}
 
# Intersection
print(s1.intersection(s2))  # {3}
 
# Difference
print(s1.difference(s2))  # {1, 2}

Operations complexity (Time Complexity)

• Add: O(1)
• Remove: O(1)
• Contains: O(1)
• Union: O(n)
• Intersection: O(n)
• Difference: O(n)