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 <= A.length <= 20
1 <= A[0].length <= 20
A[i][j]
is0
or1
.
Rust Solution
struct Solution;
impl Solution {
fn matrix_score(a: Vec<Vec<i32>>) -> i32 {
let n = a.len();
let m = a[0].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][0] { 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);
}
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