[Leetcode] Set Matrix Zeroes

Given a m x n Matrix, if an element was 0, set its entire row and column to 0. Do it on place.

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Follow up:

Did you use extra space?
A straight forward solution using O (mn) space is probably a bad idea.
A Simple Improvement uses O (m + n) space, but still is not the best solution.
Could you devise a constant space solution?

Idea: The main study is the space complexity,

Method One: Use Rowhaszero to record whether this line has 0 existence, with Colhaszero record whether this column has 0 existence. The back handles Rowhaszero and Colhaszero. Space complexity O (m+n)

classSolution { Public:        voidSetzeroes (vector<vector<int> > &matrix) {size_t row=matrix.size (); if(Row = =0)                return; size_t Col= matrix[0].size (); Vector<BOOL> Rowhaszero (Row,false); Vector<BOOL> Colhaszero (col,false);  for(inti =0; i < row; i++)            {                    for(intj =0; J < Col; J + +)                {                       if(Matrix[i][j] = =0) {Rowhaszero[i]=true; COLHASZERO[J]=true; }                   }               }                for(inti =0; i < row; i++)            {                   if(Rowhaszero[i]) { for(intj =0; J < Col; J + +) {Matrix[i][j]=0; }                   }               }                for(inti =0; I < col; i++)            {                if(Colhaszero[i]) { for(intj =0; J < Row; J + +) {Matrix[j][i]=0; }                }            }        }};

Method Two: Space complexity O (1), with the No. 0 row to record whether the column has 0, with the No. 0 column record row whether there is 0, first determine whether row 0 and column 0 is 0, and then process the matrix, if MATRIX[I][J] is 0, set matrix[i][0] = 0; MATRIX[0][J] = 0; and then according to Matrix[i][0] and Matrix[0][j] to set the corresponding row, column 0, and finally the row 0, column 0.

classSolution { Public:        voidSetzeroes (vector<vector<int> > &matrix) {size_t row=matrix.size (); if(Row = =0)                return; size_t Col= matrix[0].size (); BOOLRowzerohaszero =false; BOOLColzerohaszero =false;  for(inti =0; I < col; i++)            {                if(matrix[0][i] = =0) {Rowzerohaszero=true;  Break; }            }             for(inti =0; i < row; i++)            {                if(matrix[i][0] ==0) {Colzerohaszero=true;  Break; }            }            //cout << Rowzerohaszero << Endl; //cout << colzerohaszero << Endl;             for(inti =1; i < row; i++)            {                 for(intj =1; J < Col; J + +)                {                    if(Matrix[i][j] = =0) {matrix[i][0] =0; matrix[0][J] =0; }                }            }             for(inti =1; i < row; i++)            {                if(matrix[i][0] ==0)                {                     for(intj =0; J < Col; J + +) {Matrix[i][j]=0; }                }            }             for(inti =1; I < col; i++)            {                if(matrix[0][i] = =0)                {                     for(intj =0; J < Row; J + +) {Matrix[j][i]=0; }                }            }            //Handle the first row & first Col            if(Rowzerohaszero) { for(intj =0; J < Col; J + +) {matrix[0][J] =0; }            }            if(Colzerohaszero) { for(inti =0; i < row; i++) {matrix[i][0] =0; }            }        }};

[Leetcode] Set Matrix Zeroes