1913\. Maximum Product Difference Between Two Pairs

Easy

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:**

*   <code>4 <= nums.length <= 10<sup>4</sup></code>
*   <code>1 <= nums[i] <= 10<sup>4</sup></code>