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# 1913. Maximum Product Difference Between Two Pairs

<https://leetcode.com/problems/maximum-product-difference-between-two-pairs>

## Description

The **product difference** between two pairs `(a, b)` and `(c, d)` is defined as `(a * b) - (c * d)`.

* For example, the product difference between `(5, 6)` and `(2, 7)` is `(5 * 6) - (2 * 7) = 16`.

Given an integer array `nums`, choose four **distinct** indices `w`, `x`, `y`, and `z` such that the **product difference** between pairs `(nums[w], nums[x])` and `(nums[y], nums[z])` is **maximized**.

Return *the **maximum** such product difference*.

**Example 1:**

```

**Input:** nums = [5,6,2,7,4]
**Output:** 34
**Explanation:** We can choose indices 1 and 3 for the first pair (6, 7) and indices 2 and 4 for the second pair (2, 4).
The product difference is (6 * 7) - (2 * 4) = 34.
```

**Example 2:**

```

**Input:** nums = [4,2,5,9,7,4,8]
**Output:** 64
**Explanation:** We can choose indices 3 and 6 for the first pair (9, 8) and indices 1 and 5 for the second pair (2, 4).
The product difference is (9 * 8) - (2 * 4) = 64.
```

**Constraints:**

* `4 <= nums.length <= 104`
* `1 <= nums[i] <= 104`

## ac

```java
```