Time Complexity It does not measure absolute runtime in seconds, but rather a mathematical function describing how an algorithm's runtime grows with input size $n$. It is grounded in the core principle that algorithm analysis is a metric independent of implementation.
Why Is It the Universal Language?
- Quantitative Evolution: Big O notation ignores lower-order terms and constants, focusing solely onOrder of Magnitude.
- Deterministic Measurement: Programmers typically useWorst Case as the benchmark, providing a guaranteed performance floor.
- Cross-Environment Decision-Making: Whether on supercomputers or embedded chips, optimizing from $O(n^2)$ to $O(n \log n)$ yields fundamentally significant gains.
Counting Method
Count the occurrences of each character in two strings. If the character count lists match, the strings are definitively anagrams. This method achieves Counting Method: $O(n)$ efficiency.