The Matrix Maximum Rectangle Area

Given a binary matrix, calculate maximum size rectangle area in a binary-sub-matrix with all 1’s. Your function should return an integer denoting the area of the maximum rectangle.

Example:

0 1 1 0
1 1 1 1
1 1 1 1
1 1 0 0
the max size rectangle is
1 1 1 1
1 1 1 1
Area is 4 * 2 = 8

Solution:
Problem become simple when we use Largest Rectangle.

Algorithm:

• Take an array temp of same size of matrix.
• Set MaxArea = 0
• Iterate matrix row (i) from 0 to n – 1
  • Iterate matrix each col (j) for ith row
    • If matrix[i][j] > 0 then
      • temp[j] += matrix[i][j]
    • Else
      • temp[j] = 0
  • calculate area = LargestRectangle.calculate(temp)
  • If MaxArea < area then
    • Set MaxArea = area
• Return MaxArea

Matrix Maximum Rectangle Area

Latest Source Code:
Github: MaxRectangle.java

Output:

9