Class Solution


  • public class Solution
    extends Object
    1277 - Count Square Submatrices with All Ones.

    Medium

    Given a m * n matrix of ones and zeros, return how many square submatrices have all ones.

    Example 1:

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

    Output: 15

    Explanation:

    There are 10 squares of side 1.

    There are 4 squares of side 2.

    There is 1 square of side 3.

    Total number of squares = 10 + 4 + 1 = 15.

    Example 2:

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

    Output: 7

    Explanation:

    There are 6 squares of side 1.

    There is 1 square of side 2.

    Total number of squares = 6 + 1 = 7.

    Constraints:

    • 1 <= arr.length <= 300
    • 1 <= arr[0].length <= 300
    • 0 <= arr[i][j] <= 1
    • Constructor Detail

      • Solution

        public Solution()
    • Method Detail

      • countSquares

        public int countSquares​(int[][] matrix)