Tue. Mar 28th, 2023

# LeetCode – Arrays – Cells with Odd Values in a Matrix

#### ByKnight Coderz

Apr 2, 2020

Given `n` and `m` which are the dimensions of a matrix initialized by zeros and given an array `indices` where `indices[i] = [ri, ci]`. For each pair of `[ri, ci]` you have to increment all cells in row `ri` and column `ci` by 1.

Return the number of cells with odd values in the matrix after applying the increment to all `indices`.

Example 1:

```Input: n = 2, m = 3, indices = [[0,1],[1,1]]
Output: 6
Explanation: Initial matrix = [[0,0,0],[0,0,0]].
After applying first increment it becomes [[1,2,1],[0,1,0]].
The final matrix will be [[1,3,1],[1,3,1]] which contains 6 odd numbers.
```

Example 2:

```Input: n = 2, m = 2, indices = [[1,1],[0,0]]
Output: 0
Explanation: Final matrix = [[2,2],[2,2]]. There is no odd number in the final matrix.```
``class Solution {    public int oddCells(int n, int m, int[][] indices) {        int[][] matrix = new int[n][m];        for(int i=0;i<n;i++){            for(int j=0;j<m;j++){                matrix[i][j] = 0;            }        }                for(int[] index: indices){            int row = index[0];            int col = index[1];            for(int c=0;c<m;c++){                matrix[row][c]++;            }            for(int r=0;r<n;r++){                matrix[r][col]++;            }        }        int counter = 0;        for(int i=0;i<n;i++){            for(int j=0;j<m;j++){                if(matrix[i][j]%2 != 0) counter++;            }        }                return counter;        }}``