1768. Merge Strings Alternately: AC

Author: tan-wei

src/solution/mod.rs

@@ -1332,3 +1332,4 @@ mod s1763_longest_nice_substring;
 mod s1764_form_array_by_concatenating_subarrays_of_another_array;
 mod s1765_map_of_highest_peak;
 mod s1766_tree_of_coprimes;
+mod s1768_merge_strings_alternately;

src/solution/s1768_merge_strings_alternately.rs

@@ -0,0 +1,117 @@
+/**
+ * [1768] Merge Strings Alternately
+ *
+ * You are given two strings word1 and word2. Merge the strings by adding letters in alternating order, starting with word1. If a string is longer than the other, append the additional letters onto the end of the merged string.
+ *
+ * Return the merged string.
+ *
+ *  
+ * Example 1:
+ *
+ *
+ * Input: word1 = "abc", word2 = "pqr"
+ * Output: "apbqcr"
+ * Explanation: The merged string will be merged as so:
+ * word1:  a   b   c
+ * word2:    p   q   r
+ * merged: a p b q c r
+ *
+ *
+ * Example 2:
+ *
+ *
+ * Input: word1 = "ab", word2 = "pqrs"
+ * Output: "apbqrs"
+ * Explanation: Notice that as word2 is longer, "rs" is appended to the end.
+ * word1:  a   b
+ * word2:    p   q   r   s
+ * merged: a p b q   r   s
+ *
+ *
+ * Example 3:
+ *
+ *
+ * Input: word1 = "abcd", word2 = "pq"
+ * Output: "apbqcd"
+ * Explanation: Notice that as word1 is longer, "cd" is appended to the end.
+ * word1:  a   b   c   d
+ * word2:    p   q
+ * merged: a p b q c   d
+ *
+ *
+ *  
+ * Constraints:
+ *
+ *
+ * 	1 <= word1.length, word2.length <= 100
+ * 	word1 and word2 consist of lowercase English letters.
+ *
+ */
+pub struct Solution {}
+
+// problem: https://leetcode.com/problems/merge-strings-alternately/
+// discuss: https://leetcode.com/problems/merge-strings-alternately/discuss/?currentPage=1&orderBy=most_votes&query=
+
+// submission codes start here
+
+impl Solution {
+    pub fn merge_alternately(word1: String, word2: String) -> String {
+        let mut chars1 = word1.chars();
+        let mut chars2 = word2.chars();
+
+        let common_len = word1.len().min(word2.len());
+
+        let zipped = std::iter::zip(
+            chars1.by_ref().take(common_len),
+            chars2.by_ref().take(common_len),
+        );
+
+        let mut result = String::with_capacity(word1.len() + word2.len());
+        zipped.for_each(|(a, b)| {
+            result.push(a);
+            result.push(b)
+        });
+
+        result.extend(chars1);
+        result.extend(chars2);
+
+        result
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_1768_example_1() {
+        let word1 = "abc".to_string();
+        let word2 = "pqr".to_string();
+
+        let result = "apbqcr".to_string();
+
+        assert_eq!(Solution::merge_alternately(word1, word2), result);
+    }
+
+    #[test]
+    fn test_1768_example_2() {
+        let word1 = "ab".to_string();
+        let word2 = "pqrs".to_string();
+
+        let result = "apbqrs".to_string();
+
+        assert_eq!(Solution::merge_alternately(word1, word2), result);
+    }
+
+    #[test]
+    fn test_1768_example_3() {
+        let word1 = "abcd".to_string();
+        let word2 = "pq".to_string();
+
+        let result = "apbqcd".to_string();
+
+        assert_eq!(Solution::merge_alternately(word1, word2), result);
+    }
+}