Package g3101_3200.s3128_right_triangles

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    3128 - Right Triangles.

    Medium

    You are given a 2D boolean matrix grid.

    Return an integer that is the number of right triangles that can be made with the 3 elements of grid such that all of them have a value of 1.

    Note:

    • A collection of 3 elements of grid is a right triangle if one of its elements is in the same row with another element and in the same column with the third element. The 3 elements do not have to be next to each other.

    Example 1:

    0 1 0

    0 1 1

    0 1 0

    0 1 0

    0 1 1

    0 1 0

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

    Output: 2

    Explanation:

    There are two right triangles.

    Example 2:

    1 0 0 0

    0 1 0 1

    1 0 0 0

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

    Output: 0

    Explanation:

    There are no right triangles.

    Example 3:

    1 0 1

    1 0 0

    1 0 0

    1 0 1

    1 0 0

    1 0 0

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

    **Output: **2

    Explanation:

    There are two right triangles.

    Constraints:

    • 1 <= grid.length <= 1000

    • 1 <= grid[i].length <= 1000

    • 0 <= grid[i][j] <= 1

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final Long numberOfRightTriangles(Array<IntArray> grid)

      • Methods inherited from class java.lang.Object

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