1556. Thousand Separator: AC

Author: tan-wei

src/solution/mod.rs

@@ -1172,3 +1172,4 @@ mod s1550_three_consecutive_odds;
 mod s1551_minimum_operations_to_make_array_equal;
 mod s1552_magnetic_force_between_two_balls;
 mod s1553_minimum_number_of_days_to_eat_n_oranges;
+mod s1556_thousand_separator;

src/solution/s1556_thousand_separator.rs

@@ -0,0 +1,65 @@
+/**
+ * [1556] Thousand Separator
+ *
+ * Given an integer n, add a dot (".") as the thousands separator and return it in string format.
+ *  
+ * Example 1:
+ *
+ * Input: n = 987
+ * Output: "987"
+ *
+ * Example 2:
+ *
+ * Input: n = 1234
+ * Output: "1.234"
+ *
+ *  
+ * Constraints:
+ *
+ * 	0 <= n <= 2^31 - 1
+ *
+ */
+pub struct Solution {}
+
+// problem: https://leetcode.com/problems/thousand-separator/
+// discuss: https://leetcode.com/problems/thousand-separator/discuss/?currentPage=1&orderBy=most_votes&query=
+
+// submission codes start here
+
+impl Solution {
+    pub fn thousand_separator(n: i32) -> String {
+        n.to_string()
+            .chars()
+            .collect::<Vec<_>>()
+            .rchunks(3)
+            .rev()
+            .map(|v| v.iter().collect::<String>())
+            .collect::<Vec<_>>()
+            .join(".")
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_1556_example_1() {
+        let n = 987;
+
+        let result = "987".to_string();
+
+        assert_eq!(Solution::thousand_separator(n), result);
+    }
+
+    #[test]
+    fn test_1556_example_2() {
+        let n = 1234;
+
+        let result = "1.234".to_string();
+
+        assert_eq!(Solution::thousand_separator(n), result);
+    }
+}