1072. Flip Columns For Maximum Number of Equal Rows

 

 

Given a ​​matrix​​ consisting of 0s and 1s, we may choose any number of columns in the matrix and flip every cell in that column.  Flipping a cell changes the value of that cell from 0 to 1 or from 1 to 0.

Return the maximum number of rows that have all values equal after some number of flips.

 

Example 1:

Input: [[0,1],[1,1]]
Output: 1
Explanation: After flipping no values, 1 row has all values equal.

Example 2:

Input: [[0,1],[1,0]]
Output: 2
Explanation: After flipping values in the first column, both rows have equal values.

Example 3:

Input: [[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.
class Solution {
public:
    int maxEqualRowsAfterFlips(vector<vector<int>>& matrix) {
        int n = matrix.size();
        int m = matrix[0].size();
        int Result = 0;

        unordered_map<string,int> Map;

        for(int i = 0;i < n;i ++){
            string tmp;
            for(int j = 0;j < m;j ++){
                tmp += to_string(matrix[i][0] ^ matrix[i][j]);
            }
            Map[tmp] ++;
            Result = max(Result,Map[tmp]);
        }
        return Result;
    }
};