Set Matrix Zeros.java

#3. Optimal Approach
Complexity
Time complexity:O(2*(N*M))
Space complexity:O(1)

class Solution {
   
    public void setZeroes(int[][] matrix) {
        int m = matrix.length;
        int n = matrix[0].length;
        int col0 = 1;

        for(int i = 0;i<m;i++){
            for(int j = 0;j<n;j++){
                if(matrix[i][j]==0){  
                    matrix[i][0] = 0;
                if(j != 0){
                    matrix[0][j] = 0;
                }else col0 = 0;
                }
            }
        }
		
        for(int i = 1;i<m;i++){
            for(int j = 1;j<n;j++){
                if(matrix[i][j]!=0){
                    if(matrix[i][0]==0 ||matrix[0][j]==0)
                    {
                    matrix[i][j] = 0;
                    }
                } 
            }
        }
        for(int i = 0;i<n;i++){
            if(matrix[0][0]==0){
                matrix[0][i] = 0;
            }
        }
        for(int i = 0;i<m;i++){
            if(col0 == 0){
                matrix[i][0]=0;
            }
        }
    }