861. Score After Flipping Matrix

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題目敘述

You are given an m x n binary matrix grid.

A move consists of choosing any row or column and toggling each value in that row or column (i.e., changing all 0’s to 1’s, and all 1’s to 0’s).

Every row of the matrix is interpreted as a binary number, and the score of the matrix is the sum of these numbers.

Return the highest possible score after making any number of moves (including zero moves).

Example 1

Input: grid = [[0,0,1,1],[1,0,1,0],[1,1,0,0]] Output: 39 Explanation: 0b1111 + 0b1001 + 0b1111 = 15 + 9 + 15 = 39

Example 2

Input: grid = [[0]] Output: 1

解題思路

Solution

class Solution {
    public int matrixScore(int[][] grid) {
        int row = grid.length, col = grid[0].length, ans = 0;

        for(int i = 0; i < row; i++){
            if(grid[i][0] == 0) Flipping(grid, col, i, true);
        }

        for(int i = 0; i < col; i++){
            int zero = 0;
            for(int j = 0; j < row; j++) if(grid[j][i] == 0) zero++;
            if(row / 2 < zero) Flipping(grid, row, i, false);
        }
        
        for(int i = 0; i < row; i++){
            int tmp = 0;
            for(int j = 0; j < col; j++) tmp = tmp * 2 + grid[i][j]; 
            ans += tmp;
        }

        return ans;
    }

    private void Flipping(int[][] grid, int len, int i, boolean isRow){
        for(int j = 0; j < len; j++){
            if(isRow) grid[i][j] = grid[i][j] ^ 1;
            else grid[j][i] = grid[j][i] ^ 1;
        }
    }
}