## 1131. Maximum of Absolute Value Expression

Given two arrays of integers with equal lengths, return the maximum value of:

`|arr1[i] - arr1[j]| + |arr2[i] - arr2[j]| + |i - j|`

where the maximum is taken over all `0 <= i, j < arr1.length`.

Example 1:

```Input: arr1 = [1,2,3,4], arr2 = [-1,4,5,6]
Output: 13
```

Example 2:

```Input: arr1 = [1,-2,-5,0,10], arr2 = [0,-2,-1,-7,-4]
Output: 20
```

Constraints:

• `2 <= arr1.length == arr2.length <= 40000`
• `-10^6 <= arr1[i], arr2[i] <= 10^6`

## Rust Solution

``````struct Solution;

impl Solution {
fn max_abs_val_expr(arr1: Vec<i32>, arr2: Vec<i32>) -> i32 {
let n = arr1.len();
let max1 = (0..n).map(|i| arr1[i] + arr2[i] + i as i32).max().unwrap();
let min1 = (0..n).map(|i| arr1[i] + arr2[i] + i as i32).min().unwrap();
let max2 = (0..n).map(|i| arr1[i] + arr2[i] - i as i32).max().unwrap();
let min2 = (0..n).map(|i| arr1[i] + arr2[i] - i as i32).min().unwrap();
let max3 = (0..n).map(|i| arr1[i] - arr2[i] + i as i32).max().unwrap();
let min3 = (0..n).map(|i| arr1[i] - arr2[i] + i as i32).min().unwrap();
let max4 = (0..n).map(|i| arr1[i] - arr2[i] - i as i32).max().unwrap();
let min4 = (0..n).map(|i| arr1[i] - arr2[i] - i as i32).min().unwrap();
vec![max1 - min1, max2 - min2, max3 - min3, max4 - min4]
.into_iter()
.max()
.unwrap()
}
}

#[test]
fn test() {
let arr1 = vec![1, 2, 3, 4];
let arr2 = vec![-1, 4, 5, 6];
let res = 13;
assert_eq!(Solution::max_abs_val_expr(arr1, arr2), res);
let arr1 = vec![1, -2, -5, 0, 10];
let arr2 = vec![0, -2, -1, -7, -4];
let res = 20;
assert_eq!(Solution::max_abs_val_expr(arr1, arr2), res);
}
``````

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