1001. Grid Illumination
Read the full problem statement on LeetCode.
Difficulty: hard Acceptance: 38% Topics: Array, Hash Table
View full problem on LeetCode Reading material
Reference solution (spoiler · python)
# Time: O(l + q)
# Space: O(l)
import collections
class Solution(object):
def gridIllumination(self, N, lamps, queries):
"""
:type N: int
:type lamps: List[List[int]]
:type queries: List[List[int]]
:rtype: List[int]
"""
lookup = set()
row = collections.defaultdict(int)
col = collections.defaultdict(int)
diag = collections.defaultdict(int)
anti = collections.defaultdict(int)
for r, c in lamps:
if (r, c) in lookup:
continue
lookup.add((r, c))
row[r] += 1
col[c] += 1
diag[r-c] += 1
anti[r+c] += 1
result = []
for r, c in queries:
if not (row[r] or col[c] or diag[r-c] or anti[r+c]):
result.append(0)
continue
result.append(1)
for nr in xrange(max(r-1, 0), min(r+1, N-1)+1):
for nc in xrange(max(c-1, 0), min(c+1, N-1)+1):
if (nr, nc) not in lookup:
continue
lookup.remove((nr, nc))
row[nr] -= 1
col[nc] -= 1
diag[nr-nc] -= 1
anti[nr+nc] -= 1
return result
Solution from kamyu104/LeetCode-Solutions · MIT
Similar questions