Package g1501_1600.s1504_count_submatrices_with_all_ones

Class Solution

java.lang.Object
g1501_1600.s1504_count_submatrices_with_all_ones.Solution
public class Solution extends java.lang.Object
1504 - Count Submatrices With All Ones.

Medium

Given an m x n binary matrix mat, return the number of submatrices that have all ones.

Example 1:

Input: mat = [[1,0,1],[1,1,0],[1,1,0]]

Output: 13

Explanation:

There are 6 rectangles of side 1x1.

There are 2 rectangles of side 1x2.

There are 3 rectangles of side 2x1.

There is 1 rectangle of side 2x2.

There is 1 rectangle of side 3x1.

Total number of rectangles = 6 + 2 + 3 + 1 + 1 = 13.

Example 2:

Input: mat = [[0,1,1,0],[0,1,1,1],[1,1,1,0]]

Output: 24

Explanation:

There are 8 rectangles of side 1x1.

There are 5 rectangles of side 1x2.

There are 2 rectangles of side 1x3.

There are 4 rectangles of side 2x1.

There are 2 rectangles of side 2x2.

There are 2 rectangles of side 3x1.

There is 1 rectangle of side 3x2.

Total number of rectangles = 8 + 5 + 2 + 4 + 2 + 2 + 1 = 24.

Constraints:

  • 1 <= m, n <= 150
  • mat[i][j] is either 0 or 1.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    numSubmat(int[][] mat)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • numSubmat

      public int numSubmat(int[][] mat)