1913. Maximum Product Difference Between Two Pairs: AC

Author: tan-wei

src/solution/mod.rs

@@ -1442,3 +1442,4 @@ mod s1909_remove_one_element_to_make_the_array_strictly_increasing;
 mod s1910_remove_all_occurrences_of_a_substring;
 mod s1911_maximum_alternating_subsequence_sum;
 mod s1912_design_movie_rental_system;
+mod s1913_maximum_product_difference_between_two_pairs;

src/solution/s1913_maximum_product_difference_between_two_pairs.rs

@@ -0,0 +1,80 @@
+/**
+ * [1913] Maximum Product Difference Between Two Pairs
+ *
+ * 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 <= 10^4
+ * 	1 <= nums[i] <= 10^4
+ *
+ */
+pub struct Solution {}
+
+// problem: https://leetcode.com/problems/maximum-product-difference-between-two-pairs/
+// discuss: https://leetcode.com/problems/maximum-product-difference-between-two-pairs/discuss/?currentPage=1&orderBy=most_votes&query=
+
+// submission codes start here
+
+impl Solution {
+    pub fn max_product_difference(nums: Vec<i32>) -> i32 {
+        let mut nums = nums;
+        nums.sort_unstable();
+        let n = nums.len();
+        nums[n - 1] * nums[n - 2] - nums[0] * nums[1]
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_1913_example_1() {
+        let nums = vec![5, 6, 2, 7, 4];
+
+        let result = 34;
+
+        assert_eq!(Solution::max_product_difference(nums), result);
+    }
+
+    #[test]
+    fn test_1913_example_2() {
+        let nums = vec![4, 2, 5, 9, 7, 4, 8];
+
+        let result = 64;
+
+        assert_eq!(Solution::max_product_difference(nums), result);
+    }
+}