def _levenshtein(self, a: List, b: List) -> int:
        """Calculates the Levenshtein distance between a and b."""
        n, m = len(a), len(b)
        if n > m:
            # Make sure n <= m, to use O(min(n,m)) space
            a, b = b, a
            n, m = m, n

        current = list(range(n + 1))
        for i in range(1, m + 1):
            previous, current = current, [i] + [0] * n
            for j in range(1, n + 1):
                add, delete = previous[j] + 1, current[j - 1] + 1
                change = previous[j - 1]
                if a[j - 1] != b[i - 1]:
                    change = change + 1
                current[j] = min(add, delete, change)

        return current[n]
Calculates the Levenshtein distance between a and b.
examples/cpu/llm/inference/single_instance/run_accuracy.py