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Special Cells in Binary Matrix
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30 mins
2 upvotes
Matrices (2D Arrays)
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Special Cells in Binary Matrix

Contributed by
srejanbera
Easy
yellow-spark
0/40
Avg time to solve 30 mins
Success Rate 75 %
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2 upvotes

Problem Statement

Ninja is observing a Binary matrix of size N * M . A Binary Matrix is made up of only 0’s and 1’s. Ninja wants to know the number of special cells in the matrix. The conditions of a cell to be a special cell are:

The value of M[i][j] should be 1.
All other cells of row i should be 0.
All other cells of column j should be 0.

You are given the matrix ‘MAT’ of size N * M. Your task is to find the number of special cells in the given matrix.

For Example
For the matrix :
  1  0  0
  0  0  0
  0  1  0

The Answer will be 2 as cell (0,0) and (2,1) are special.(Indexing is 0 based). 
Detailed explanation ( Input/output format, Notes, Constraints, Images )
Sample Input 1:
2
3 3
1 0 0
0 0 0
0 1 0
4 3
1 0 0
0 0 1
0 0 0
0 1 1
Sample Output 1:
2
1
Explanation of sample input 1:
For the first test case,
There are two special cells having index (0,0) and (2,1).Hence, the answer is 2.

For the second test case:
There is only one cell that is special having an index (0,0). Hence, the answer is 1.
Hence the answer is 3.
Sample Input 2:
2
4 4
0 1 0 0 
0 0 0 0 
0 0 0 0 
0 0 0 1 
4 3
0 1 0 
0 0 1 
0 1 0 
0 0 0 
Sample Output 2:
2
1
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