1749. Maximum Absolute Sum of Any Subarray

You are given an integer array `nums`. The absolute sum of a subarray `[numsl, numsl+1, ..., numsr-1, numsr]` is `abs(numsl + numsl+1 + ... + numsr-1 + numsr)`.

Return the maximum absolute sum of any (possibly empty) subarray of `nums`.

Note that `abs(x)` is defined as follows:

• If `x` is a negative integer, then `abs(x) = -x`.
• If `x` is a non-negative integer, then `abs(x) = x`.

Example 1:

```Input: nums = [1,-3,2,3,-4]
Output: 5
Explanation: The subarray [2,3] has absolute sum = abs(2+3) = abs(5) = 5.
```

Example 2:

```Input: nums = [2,-5,1,-4,3,-2]
Output: 8
Explanation: The subarray [-5,1,-4] has absolute sum = abs(-5+1-4) = abs(-8) = 8.
```

Constraints:

• `1 <= nums.length <= 105`
• `-104 <= nums[i] <= 104`

1749. Maximum Absolute Sum of Any Subarray
``````struct Solution;

impl Solution {
fn max_absolute_sum(nums: Vec<i32>) -> i32 {
let n = nums.len();
let mut sum = 0;
let mut min = 0;
let mut max = 0;
let mut sub_min = 0;
let mut sub_max = 0;
let mut res = 0;
for i in 0..n {
sum += nums[i];
min = min.min(sum);
max = max.max(sum);
sub_max = sub_max.max(sum - min);
sub_min = sub_min.min(sum - max);
res = res.max(sub_max.abs());
res = res.max(sub_min.abs());
}
res
}
}

#[test]
fn test() {
let nums = vec![1, -3, 2, 3, -4];
let res = 5;
assert_eq!(Solution::max_absolute_sum(nums), res);
let nums = vec![2, -5, 1, -4, 3, -2];
let res = 8;
assert_eq!(Solution::max_absolute_sum(nums), res);
}
``````