2174. Remove All Ones With Row and Column Flips II
Содержание
class Solution:
def removeOnes(self, grid: List[List[int]]) -> int:
m, n = len(grid), len(grid[0])
state = sum(1 << (i * n + j) for i in range(m) for j in range(n) if grid[i][j])
q = deque([state])
vis = {state}
res = 0
while q:
for _ in range(len(q)):
state = q.popleft()
if state == 0:
return res
for i in range(m):
for j in range(n):
if grid[i][j] == 0:
continue
nxt = state
for r in range(m):
nxt &= ~(1 << (r * n + j))
for c in range(n):
nxt &= ~(1 << (i * n + c))
if nxt not in vis:
vis.add(nxt)
q.append(nxt)
res += 1
return -1