Set Matrix Zeroes | GFG | LeetCode | Interviewbit | Solve in Constant Space.

 Statement - Given an m x n matrix. If an element is 0, set its entire row and column to 0. Do it in-place. 

Example 1:

Input: matrix = [[1,1,1],[1,0,1],[1,1,1]]
Output: [[1,0,1],[0,0,0],[1,0,1]]

Problem Link - LeetCode GFG InterviewBit

Code - Time Complexity O(n^2) and Space Complexity O(1).

class Solution {
public:
    void setZeroes(vector<vector<int>>& matrix) {
        
        int row = matrix.size();
        int col = matrix[0].size();
        
        bool row0 = false, col0 = false;
        
        for(int i = 0; i < row; i++)
        {
            for(int j = 0; j < col; j++)
            {
                if(matrix[i][j] == 0)
                {
                    if(i == 0) row0 = true;
                    if(j == 0) col0 =true;
                    matrix[0][j] = 0;
                    matrix[i][0] = 0;
                }
            }
        }
       for(int i = 1; i < row; i++)
        {
            for(int j = 1; j < col; j++)
            {
                if(matrix[i][0] == 0 || matrix[0][j] == 0)
                    matrix[i][j] = 0;
            }
        }
        
        
        if(row0)
        {
            for(int i = 0; i < col; i++)
                matrix[0][i] = 0;
        }
        
        if(col0)
        {
            for(int i = 0; i < row; i++)
                matrix[i][0] = 0;
        } 
    }
};