Package g1501_1600.s1582_special_positions_in_a_binary_matrix

Class Solution

java.lang.Object
g1501_1600.s1582_special_positions_in_a_binary_matrix.Solution
public class Solution extends java.lang.Object
1582 - Special Positions in a Binary Matrix.

Easy

Given an m x n binary matrix mat, return the number of special positions in mat.

A position (i, j) is called special if mat[i][j] == 1 and all other elements in row i and column j are 0 (rows and columns are 0-indexed ).

Example 1:

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

Output: 1

Explanation: (1, 2) is a special position because mat[1][2] == 1 and all other elements in row 1 and column 2 are 0.

Example 2:

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

Output: 3

Explanation: (0, 0), (1, 1) and (2, 2) are special positions.

Constraints:

  • m == mat.length
  • n == mat[i].length
  • 1 <= m, n <= 100
  • mat[i][j] is either 0 or 1.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    numSpecial(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

    • numSpecial

      public int numSpecial(int[][] mat)