Computer Science - Algorithms - Big O notation - Understanding Big O

5 sections. Section 1 'What is Big O?': Describes how algorithm performance SCALES with input size. Not exact time - just growth RATE. Ignores constants: O(2n) = O(n). Ignores lower terms: O(n² + n) = O(n²). Worst-case guarantee. Section 2 'Common Complexities': O(1): hash lookup, array access. O(lo