2014. Longest Subsequence Repeated k Times: RETRY

Author: tan-wei

src/solution/mod.rs

@@ -1518,3 +1518,4 @@ mod s2009_minimum_number_of_operations_to_make_array_continuous;
 mod s2011_final_value_of_variable_after_performing_operations;
 mod s2012_sum_of_beauty_in_the_array;
 mod s2013_detect_squares;
+mod s2014_longest_subsequence_repeated_k_times;

src/solution/s2014_longest_subsequence_repeated_k_times.rs

@@ -0,0 +1,91 @@
+/**
+ * [2014] Longest Subsequence Repeated k Times
+ *
+ * You are given a string s of length n, and an integer k. You are tasked to find the longest subsequence repeated k times in string s.
+ * A subsequence is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters.
+ * A subsequence seq is repeated k times in the string s if seq * k is a subsequence of s, where seq * k represents a string constructed by concatenating seq k times.
+ *
+ * 	For example, "bba" is repeated 2 times in the string "bababcba", because the string "bbabba", constructed by concatenating "bba" 2 times, is a subsequence of the string "<u>b</u>a<u>bab</u>c<u>ba</u>".
+ *
+ * Return the longest subsequence repeated k times in string s. If multiple such subsequences are found, return the lexicographically largest one. If there is no such subsequence, return an empty string.
+ *  
+ * Example 1:
+ * <img alt="example 1" src="https://assets.leetcode.com/uploads/2021/08/30/longest-subsequence-repeat-k-times.png" style="width: 457px; height: 99px;" />
+ * Input: s = "letsleetcode", k = 2
+ * Output: "let"
+ * Explanation: There are two longest subsequences repeated 2 times: "let" and "ete".
+ * "let" is the lexicographically largest one.
+ *
+ * Example 2:
+ *
+ * Input: s = "bb", k = 2
+ * Output: "b"
+ * Explanation: The longest subsequence repeated 2 times is "b".
+ *
+ * Example 3:
+ *
+ * Input: s = "ab", k = 2
+ * Output: ""
+ * Explanation: There is no subsequence repeated 2 times. Empty string is returned.
+ *
+ *  
+ * Constraints:
+ *
+ * 	n == s.length
+ * 	2 <= n, k <= 2000
+ * 	2 <= n < k * 8
+ * 	s consists of lowercase English letters.
+ *
+ */
+pub struct Solution {}
+
+// problem: https://leetcode.com/problems/longest-subsequence-repeated-k-times/
+// discuss: https://leetcode.com/problems/longest-subsequence-repeated-k-times/discuss/?currentPage=1&orderBy=most_votes&query=
+
+// submission codes start here
+
+impl Solution {
+    pub fn longest_subsequence_repeated_k(s: String, k: i32) -> String {
+        String::new()
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    #[ignore]
+    fn test_2014_example_1() {
+        let s = "letsleetcode".to_string();
+        let k = 2;
+
+        let result = "let".to_string();
+
+        assert_eq!(Solution::longest_subsequence_repeated_k(s, k), result);
+    }
+
+    #[test]
+    #[ignore]
+    fn test_2014_example_2() {
+        let s = "bb".to_string();
+        let k = 2;
+
+        let result = "b".to_string();
+
+        assert_eq!(Solution::longest_subsequence_repeated_k(s, k), result);
+    }
+
+    #[test]
+    #[ignore]
+    fn test_2014_example_3() {
+        let s = "ab".to_string();
+        let k = 2;
+
+        let result = "".to_string();
+
+        assert_eq!(Solution::longest_subsequence_repeated_k(s, k), result);
+    }
+}