class Solution:
    def largestSubmatrix(self, matrix: List[List[int]]) -> int:
        m, n = len(matrix), len(matrix[0])
        prev_heights = []
        ans = 0

        for row in range(m):
            heights, seen = [], [False] * n

            for height, col in prev_heights:
                if matrix[row][col] == 1:
                    heights.append((height + 1, col))
                    seen[col] = True
            
            for col in range(n):
                if seen[col] == False and matrix[row][col] == 1:
                    heights.append((1, col))
            
            for i in range(len(heights)):
                ans = max(ans, heights[i][0] * (i + 1))
            prev_heights = heights
        return ans