def maximalRectangle(self, matrix):

if not matrix or len(matrix)==0 or len(matrix[0])==0: return 0

count,retval,dp=0,0,[]

for i in xrange(len(matrix)):

tmp=[]

for j in xrange(len(matrix[0])):

tmp.append(int(matrix[i][j]))

dp.append(tmp)

for i in xrange(len(matrix)):

for j in xrange(len(matrix[0])):

if i> 0 and dp[i][j]==1:

dp[i][j]=dp[i-1][j]+1

retval=max(retval,dp[i][j])

retval=max(retval,self.maxhist(dp[i]))

return retval

def maxhist(self, height):

i,retval,s=0,0,[]

while i<len(height):

while len(s)>0 and height[i]<height[s[-1]]:

tmp=height[s.pop()]*(i if len(s)==0 else i-s[-1]-1)

retval=max(retval,tmp)

s.append(i)

i+=1

while len(s)>0:

tmp=height[s.pop()]*(len(height) if len(s)==0 else len(height)-s[-1]-1)

retval=max(retval,tmp)