题目描述
给定一个仅包含 0 和 1 的二维二进制矩阵,找出只包含 1 的最大矩形,并返回其面积。
示例:
输入:
[
[“1”,“0”,“1”,“0”,“0”],
[“1”,“0”,“1”,“1”,“1”],
[“1”,“1”,“1”,“1”,“1”],
[“1”,“0”,“0”,“1”,“0”]
]
输出: 6
思路
代码
class Solution:
def maxmalRectangle(self , matrix):
m = len(matrix)
n = len(matrix[0])
maxarea = 0
dp = [[0]*n for _ in range(m)]
for i in range(m):
for j in range(n):
if matrix[i][j] == 0:
continue
width = dp[i][j] = dp[i][j-1] + 1 if j else 1
for k in range(i,-1,-1):
width = min(width , dp[k][j])
maxarea = max(maxarea , width*(i - k + 1))
return maxarea
test = Solution()
test.maxmalRectangle([
[1,0,1,0,0],
[1,0,1,1,1],
[1,1,1,1,1],
[1,0,0,1,0]
])