Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in place.
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 not the best
solution.
Could you devise a constant space solution?
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class
Solution {public: void
setZeroes(vector<vector<int> > &matrix) { int
flag1 = 0; int
flag0 = 0; for(int
i = 0 ; i < matrix.size();i++) if(matrix[i][0] == 0)flag1 = 1; for(int
i = 0 ; i < matrix[0].size();i++) if(matrix[0][i] == 0)flag0 = 1; for(int
i = 1 ; i < matrix.size();i++) for(int
j = 1 ; j < matrix[0].size();j++) { if(matrix[i][j] == 0) { matrix[0][j] = 0; matrix[i][0] = 0; } } for(int
i = 1 ; i < matrix.size();i++) { if(matrix[i][0] == 0) for(int
j = 1 ; j < matrix[i].size();j++)matrix[i][j]=0; } for(int
i = 1 ; i < matrix[0].size();i++) { if(matrix[0][i] == 0) for(int
j = 1 ; j < matrix.size();j++)matrix[j][i]=0; } if(flag1 == 1)for(int
i = 0 ; i < matrix.size();i++)matrix[i][0] = 0; if(flag0 == 1)for(int
i = 0 ; i < matrix[0].size();i++)matrix[0][i] = 0; }}; |
Set Matrix Zeroes,布布扣,bubuko.com
原文：http://www.cnblogs.com/pengyu2003/p/3596314.html