The product difference between two pairs (a, b) and (c, d) is defined as (a * b) - (c * d).
(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 <= 1041 <= nums[i] <= 104struct Solution;
impl Solution {
fn max_product_difference(mut nums: Vec<i32>) -> i32 {
let n = nums.len();
nums.sort_unstable();
nums[n - 1] * nums[n - 2] - nums[0] * nums[1]
}
}
#[test]
fn test() {
let nums = vec![5, 6, 2, 7, 4];
let res = 34;
assert_eq!(Solution::max_product_difference(nums), res);
let nums = vec![4, 2, 5, 9, 7, 4, 8];
let res = 64;
assert_eq!(Solution::max_product_difference(nums), res);
}