#1072
Flip Columns For Maximum Number of Equal Rows
medium · verified · 78.6% accepted · 1,344 likes · top 90%
array · hash table · matrix
Description
You are given an m x n binary matrix matrix.
You can choose any number of columns in the matrix and flip every cell in that column (i.e., Change the value of the cell from 0 to 1 or vice versa).
Return the maximum number of rows that have all values equal after some number of flips.
Example 1:
Input: matrix = [[0,1],[1,1]]
Output: 1
Explanation: After flipping no values, 1 row has all values equal.
Example 2:
Input: matrix = [[0,1],[1,0]]
Output: 2
Explanation: After flipping values in the first column, both rows have equal values.
Example 3:
Input: matrix = [[0,0,0],[0,0,1],[1,1,0]]
Output: 2
Explanation: After flipping values in the first two columns, the last two rows have equal values.
Solution