Same signature as v2/v3, but now n may be negative. Real head -n -K prints all lines except the last K. So when n < 0 return all lines except the last |n|; when n ≥ 0 behave exactly like v3 (return the first n, capped at the input length). If |n| is at least the number of lines, nothing is left, so return the empty string.
Function signature:
def head(self, lines: List[str], n: int) -> str:
Example (negative n):
Input: lines = ["a", "b", "c", "d", "e"], n = -2 Output: "a\nb\nc" When printed: a b c
Python's slice
lines[:n] already does the right thing for both signs. When n is negative, the slice means "stop |n| from the end" — exactly what we want.
The full solution is the exact same one-liner from v2/v3:
class Solution:
def head(self, lines, n):
return "\n".join(lines[:n])
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