2284. Sender With Largest Word Count: RETRY, credit: https://leetcode.com/problems/sender-with-largest-word-count/solutions/5300813/two-line-solution-beats-88-at-speed-hash-gr14/

Author: tan-wei

src/solution/mod.rs

@@ -1730,3 +1730,4 @@ mod s2279_maximum_bags_with_full_capacity_of_rocks;
 mod s2280_minimum_lines_to_represent_a_line_chart;
 mod s2281_sum_of_total_strength_of_wizards;
 mod s2283_check_if_number_has_equal_digit_count_and_digit_value;
+mod s2284_sender_with_largest_word_count;

src/solution/s2284_sender_with_largest_word_count.rs

@@ -0,0 +1,113 @@
+/**
+ * [2284] Sender With Largest Word Count
+ *
+ * You have a chat log of n messages. You are given two string arrays messages and senders where messages[i] is a message sent by senders[i].
+ * A message is list of words that are separated by a single space with no leading or trailing spaces. The word count of a sender is the total number of words sent by the sender. Note that a sender may send more than one message.
+ * Return the sender with the largest word count. If there is more than one sender with the largest word count, return the one with the lexicographically largest name.
+ * Note:
+ *
+ * 	Uppercase letters come before lowercase letters in lexicographical order.
+ * 	"Alice" and "alice" are distinct.
+ *
+ *  
+ * Example 1:
+ *
+ * Input: messages = ["Hello userTwooo","Hi userThree","Wonderful day Alice","Nice day userThree"], senders = ["Alice","userTwo","userThree","Alice"]
+ * Output: "Alice"
+ * Explanation: Alice sends a total of 2 + 3 = 5 words.
+ * userTwo sends a total of 2 words.
+ * userThree sends a total of 3 words.
+ * Since Alice has the largest word count, we return "Alice".
+ *
+ * Example 2:
+ *
+ * Input: messages = ["How is leetcode for everyone","Leetcode is useful for practice"], senders = ["Bob","Charlie"]
+ * Output: "Charlie"
+ * Explanation: Bob sends a total of 5 words.
+ * Charlie sends a total of 5 words.
+ * Since there is a tie for the largest word count, we return the sender with the lexicographically larger name, Charlie.
+ *  
+ * Constraints:
+ *
+ * 	n == messages.length == senders.length
+ * 	1 <= n <= 10^4
+ * 	1 <= messages[i].length <= 100
+ * 	1 <= senders[i].length <= 10
+ * 	messages[i] consists of uppercase and lowercase English letters and ' '.
+ * 	All the words in messages[i] are separated by a single space.
+ * 	messages[i] does not have leading or trailing spaces.
+ * 	senders[i] consists of uppercase and lowercase English letters only.
+ *
+ */
+pub struct Solution {}
+
+// problem: https://leetcode.com/problems/sender-with-largest-word-count/
+// discuss: https://leetcode.com/problems/sender-with-largest-word-count/discuss/?currentPage=1&orderBy=most_votes&query=
+
+// submission codes start here
+
+impl Solution {
+    // Credit: https://leetcode.com/problems/sender-with-largest-word-count/solutions/5300813/two-line-solution-beats-88-at-speed-hash-gr14/
+    pub fn largest_word_count(messages: Vec<String>, senders: Vec<String>) -> String {
+        let generate_map = || {
+            let mut map = std::collections::HashMap::new();
+            map.insert(String::new(), 0);
+            map
+        };
+
+        senders
+            .into_iter()
+            .zip(messages.into_iter())
+            .fold(
+                (String::new(), generate_map()),
+                |(max_sender, mut map), (sender, message)| {
+                    *map.entry(sender.clone()).or_insert(0) += message.split(" ").count() as i32;
+                    let (cmp1, cmp2) = (
+                        map[&sender] > map[&max_sender],
+                        map[&sender] == map[&max_sender],
+                    );
+                    if cmp1 || cmp2 && sender > max_sender {
+                        (sender, map)
+                    } else {
+                        (max_sender, map)
+                    }
+                },
+            )
+            .0
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_2284_example_1() {
+        let messages = vec_string![
+            "Hello userTwooo",
+            "Hi userThree",
+            "Wonderful day Alice",
+            "Nice day userThree"
+        ];
+        let senders = vec_string!["Alice", "userTwo", "userThree", "Alice"];
+
+        let result = "Alice".to_string();
+
+        assert_eq!(Solution::largest_word_count(messages, senders), result);
+    }
+
+    #[test]
+    fn test_2284_example_2() {
+        let messages = vec_string![
+            "How is leetcode for everyone",
+            "Leetcode is useful for practice"
+        ];
+        let senders = vec_string!["Bob", "Charlie"];
+
+        let result = "Charlie".to_string();
+
+        assert_eq!(Solution::largest_word_count(messages, senders), result);
+    }
+}