human
Write me a code to maximum perimeter of a square in a 2D grid and the other steps required given the following:
Maximum perimeter of a square in a 2D grid | Function to calculate the perfix sum of the rows and the columns of the given matrix.
Number of rows and cols.
First column of the row prefix array.
Update the prefix sum for the rows.
First row of the column prefix array.
Update the prefix sum for the columns.
Function to return the perimeter of the square having top - left corner at ( i , j ) and size k.
i and j represent the top left corner of the square and k is the size.
Get the upper row sum.
Get the left column sum.
At the distance of k in both direction.
The perimeter will be sum of all the values.
Since all the corners are included twice , they need to be subtract from the sum.
Function to return the maximum perimeter of a square in the given matrix.
Number of rows and cols.
Function call to calculate the prefix sum of rows and cols.
To store the maximum perimeter.
Nested loops to choose the top - left corner of the square.
Loop for the size of the square.
Get the perimeter of the current square.
Update the maximum perimeter so far.
Driver code"
How can the above be solved in Python?
assistant
#Here is code to maximum perimeter of a square in a 2D grid and the other steps required.
 def perfix_calculate ( A , row , col ) :
	n = len ( A )
	m = len ( A [ 0 ] )
	for i in range ( n ) :
		row [ i ] [ 0 ] = A [ i ] [ 0 ]
	for i in range ( n ) :
		for j in range ( 1 , m ) :
			row [ i ] [ j ] = row [ i ] [ j - 1 ] + A [ i ] [ j ]
	for i in range ( m ) :
		col [ 0 ] [ i ] = A [ 0 ] [ i ]
	for i in range ( m ) :
		for j in range ( 1 , m ) :
			col [ j ] [ i ] = A [ j ] [ i ] + col [ j - 1 ] [ i ]
def perimeter ( i , j , k , row , col , A ) :
	row_s , col_s = 0 , 0
	if ( j == 0 ) :
		row_s = 0
	else :
		row_s = row [ i ] [ j - 1 ]
	if ( i == 0 ) :
		col_s = 0
	else :
		col_s = col [ i - 1 ] [ j ]
	upper_row = row [ i ] [ j + k ] - row_s
	left_col = col [ i + k ] [ j ] - col_s
	if ( j == 0 ) :
		row_s = 0
	else :
		row_s = row [ i + k ] [ j - 1 ]
	if ( i == 0 ) :
		col_s = 0
	else :
		col_s = col [ i - 1 ] [ j + k ]
	lower_row = row [ i + k ] [ j + k ] - row_s
	right_col = col [ i + k ] [ j + k ] - col_s
	sum = upper_row + lower_row + left_col + right_col
	sum -= ( A [ i ] [ j ] + A [ i + k ] [ j ] +   \ A [ i ] [ j + k ] + A [ i + k ] [ j + k ] )
	return sum
def maxPerimeter ( A ) :
	n = len ( A )
	m = len ( A [ 0 ] )
	row = [ [ 0 for i in range ( m ) ] for i in range ( n ) ]
	col = [ [ 0 for i in range ( m ) ] for i in range ( n ) ]
	perfix_calculate ( A , row , col )
	maxPer = 0
	for i in range ( n ) :
		for j in range ( m ) :
			for k in range ( min ( n - i , m - j ) ) :
				perimtr = perimeter ( i , j , k , row , col , A )
				maxPer = max ( maxPer , perimtr )
	return maxPer
A = [ [ 1 , 1 , 0 ] , [ 1 , 1 , 1 ] , [ 0 , 1 , 1 ] ]
print ( maxPerimeter ( A ) )