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Set Matrix Zeroes - Leetcode 73 - Python

 Set Matrix Zeroes


Given an m x n integer matrix matrix, if an element is 0, set its entire row and column to 0's.

You must do it in place.

 

Example :


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


class Solution:

    def setZeroes(self, m: List[List[int]]) -> None:

        """

        Do not return anything, modify matrix in-place instead.

        """

        

        #initialize

        r,c = len(m), len(m[0])

        r0 = False

        

        #set inplaces zero

        for i in range(r): 

            for j in range(c):

                if m[i][j] == 0:

                    m[0][j] = 0

                    if i > 0:

                        m[i][0] = 0

                    else:

                        r0 = True

        

        #set whole row/col 0 if inplace is zero

        for i in range(1,r):

            for j in range(1,c):

                if m[0][j] == 0 or m[i][0] == 0:

                    m[i][j] = 0

                    

        #setting zeroth col 0

        if m[0][0] == 0:

            for i in range(r):

                m[i][0] = 0

        

        #setting zeroth row 0

        if r0:

            for j in range(c):

                m[0][j] = 0



Explaination :



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