struct Solution;
impl Solution {
fn min_falling_path_sum(a: Vec<Vec<i32>>) -> i32 {
let n = a.len();
let m = a[0].len();
let mut dp = vec![vec![0; m]; n];
for i in 0..n {
for j in 0..m {
let mut min = std::i32::MAX;
if i > 0 {
let l = 0.max(j as i32 - 1) as usize;
let r = (n - 1).min(j + 1);
for k in l..=r {
min = min.min(dp[i - 1][k]);
}
} else {
min = 0;
}
dp[i][j] = a[i][j] + min;
}
}
*dp[n - 1].iter().min().unwrap()
}
}
#[test]
fn test() {
let a = vec_vec_i32![[1, 2, 3], [4, 5, 6], [7, 8, 9]];
let res = 12;
assert_eq!(Solution::min_falling_path_sum(a), res);
}