Algorithms & Complexity

Algorithms & Complexity Vocabulary

Big O Notation

Useful Phrases

• "The naive solution runs in O(n²) but we can optimize it to O(n log n) using a sorted set."
• "The space complexity is O(n) because we store all elements in the hash map."
• "This algorithm runs in linear time — it scales well for large inputs."
• "We can reduce the time complexity from O(n²) to O(n) using a two-pointer approach."