861. Score After Flipping Matrix

We have a two dimensional matrix `A` where each value is `0` or `1`.

A move consists of choosing any row or column, and toggling each value in that row or column: changing all `0`s to `1`s, and all `1`s to `0`s.

After making any number of moves, every row of this matrix is interpreted as a binary number, and the score of the matrix is the sum of these numbers.

Return the highest possible score.

Example 1:

```Input: [[0,0,1,1],[1,0,1,0],[1,1,0,0]]
Output: 39
Explanation:
Toggled to [[1,1,1,1],[1,0,0,1],[1,1,1,1]].
0b1111 + 0b1001 + 0b1111 = 15 + 9 + 15 = 39```

Note:

1. `1 <= A.length <= 20`
2. `1 <= A.length <= 20`
3. `A[i][j]` is `0` or `1`.

861. Score After Flipping Matrix
``````struct Solution;

impl Solution {
fn matrix_score(a: Vec<Vec<i32>>) -> i32 {
let n = a.len();
let m = a.len();
let mut res = n << (m - 1);
for j in 1..m {
let mut x = Self::sum_col(j, &a, n);
x = x.max(n - x);
res += x << (m - 1 - j);
}
res as i32
}
fn sum_col(j: usize, a: &[Vec<i32>], n: usize) -> usize {
let mut res = 0;
for i in 0..n {
res += if a[i][j] == a[i] { 1 } else { 0 };
}
res as usize
}
}

#[test]
fn test() {
let a = vec_vec_i32![[0, 0, 1, 1], [1, 0, 1, 0], [1, 1, 0, 0]];
let res = 39;
assert_eq!(Solution::matrix_score(a), res);
let a = vec_vec_i32![[0, 1], [0, 1], [0, 1], [0, 0]];
let res = 11;
assert_eq!(Solution::matrix_score(a), res);
}
``````