Preprocess the prefix maximum array, <code>prefix_max[i] = max(nums[0], nums[1], …, nums[i])</code> and the suffix maximum array, <code>suffix_max[i] = max(nums[i], nums[i + 1], …, nums[i - 1])</code>.

For each index <code>j</code>, find two indices <code>i</code> and <code>k</code> such that <code>i < j < k</code> and <code>(nums[i] - nums[j]) * nums[k]</code> is the maximum, using the prefix and suffix maximum arrays.

For index <code>j</code>, the maximum triplet value is <code>(prefix_max[j - 1] - nums[j]) * suffix_max[j + 1]</code>.