2097. Valid Arrangement of Pairs: RETRY

Author: tan-wei

src/solution/mod.rs

@@ -1582,3 +1582,4 @@ mod s2092_find_all_people_with_secret;
 mod s2094_finding_3_digit_even_numbers;
 mod s2095_delete_the_middle_node_of_a_linked_list;
 mod s2096_step_by_step_directions_from_a_binary_tree_node_to_another;
+mod s2097_valid_arrangement_of_pairs;

src/solution/s2097_valid_arrangement_of_pairs.rs

@@ -0,0 +1,96 @@
+/**
+ * [2097] Valid Arrangement of Pairs
+ *
+ * You are given a 0-indexed 2D integer array pairs where pairs[i] = [starti, endi]. An arrangement of pairs is valid if for every index i where 1 <= i < pairs.length, we have endi-1 == starti.
+ * Return any valid arrangement of pairs.
+ * Note: The inputs will be generated such that there exists a valid arrangement of pairs.
+ *  
+ * Example 1:
+ *
+ * Input: pairs = [[5,1],[4,5],[11,9],[9,4]]
+ * Output: [[11,9],[9,4],[4,5],[5,1]]
+ * Explanation:
+ * This is a valid arrangement since endi-1 always equals starti.
+ * end0 = 9 == 9 = start1
+ * end1 = 4 == 4 = start2
+ * end2 = 5 == 5 = start3
+ *
+ * Example 2:
+ *
+ * Input: pairs = [[1,3],[3,2],[2,1]]
+ * Output: [[1,3],[3,2],[2,1]]
+ * Explanation:
+ * This is a valid arrangement since endi-1 always equals starti.
+ * end0 = 3 == 3 = start1
+ * end1 = 2 == 2 = start2
+ * The arrangements [[2,1],[1,3],[3,2]] and [[3,2],[2,1],[1,3]] are also valid.
+ *
+ * Example 3:
+ *
+ * Input: pairs = [[1,2],[1,3],[2,1]]
+ * Output: [[1,2],[2,1],[1,3]]
+ * Explanation:
+ * This is a valid arrangement since endi-1 always equals starti.
+ * end0 = 2 == 2 = start1
+ * end1 = 1 == 1 = start2
+ *
+ *  
+ * Constraints:
+ *
+ * 	1 <= pairs.length <= 10^5
+ * 	pairs[i].length == 2
+ * 	0 <= starti, endi <= 10^9
+ * 	starti != endi
+ * 	No two pairs are exactly the same.
+ * 	There exists a valid arrangement of pairs.
+ *
+ */
+pub struct Solution {}
+
+// problem: https://leetcode.com/problems/valid-arrangement-of-pairs/
+// discuss: https://leetcode.com/problems/valid-arrangement-of-pairs/discuss/?currentPage=1&orderBy=most_votes&query=
+
+// submission codes start here
+
+impl Solution {
+    pub fn valid_arrangement(pairs: Vec<Vec<i32>>) -> Vec<Vec<i32>> {
+        vec![]
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    #[ignore]
+    fn test_2097_example_1() {
+        let pairs = vec![vec![5, 1], vec![4, 5], vec![11, 9], vec![9, 4]];
+
+        let result = vec![vec![11, 9], vec![9, 4], vec![4, 5], vec![5, 1]];
+
+        assert_eq!(Solution::valid_arrangement(pairs), result);
+    }
+
+    #[test]
+    #[ignore]
+    fn test_2097_example_2() {
+        let pairs = vec![vec![1, 3], vec![3, 2], vec![2, 1]];
+
+        let result = vec![vec![1, 3], vec![3, 2], vec![2, 1]];
+
+        assert_eq!(Solution::valid_arrangement(pairs), result);
+    }
+
+    #[test]
+    #[ignore]
+    fn test_2097_example_3() {
+        let pairs = vec![vec![1, 2], vec![1, 3], vec![2, 1]];
+
+        let result = vec![vec![1, 2], vec![2, 1], vec![1, 3]];
+
+        assert_eq!(Solution::valid_arrangement(pairs), result);
+    }
+}