2119. A Number After a Double Reversal: AC

Author: tan-wei

src/solution/mod.rs

@@ -1599,3 +1599,4 @@ mod s2114_maximum_number_of_words_found_in_sentences;
 mod s2115_find_all_possible_recipes_from_given_supplies;
 mod s2116_check_if_a_parentheses_string_can_be_valid;
 mod s2117_abbreviating_the_product_of_a_range;
+mod s2119_a_number_after_a_double_reversal;

src/solution/s2119_a_number_after_a_double_reversal.rs

@@ -0,0 +1,79 @@
+/**
+ * [2119] A Number After a Double Reversal
+ *
+ * Reversing an integer means to reverse all its digits.
+ *
+ * 	For example, reversing 2021 gives 1202. Reversing 12300 gives 321 as the leading zeros are not retained.
+ *
+ * Given an integer num, reverse num to get reversed1, then reverse reversed1 to get reversed2. Return true if reversed2 equals num. Otherwise return false.
+ *  
+ * Example 1:
+ *
+ * Input: num = 526
+ * Output: true
+ * Explanation: Reverse num to get 625, then reverse 625 to get 526, which equals num.
+ *
+ * Example 2:
+ *
+ * Input: num = 1800
+ * Output: false
+ * Explanation: Reverse num to get 81, then reverse 81 to get 18, which does not equal num.
+ *
+ * Example 3:
+ *
+ * Input: num = 0
+ * Output: true
+ * Explanation: Reverse num to get 0, then reverse 0 to get 0, which equals num.
+ *
+ *  
+ * Constraints:
+ *
+ * 	0 <= num <= 10^6
+ *
+ */
+pub struct Solution {}
+
+// problem: https://leetcode.com/problems/a-number-after-a-double-reversal/
+// discuss: https://leetcode.com/problems/a-number-after-a-double-reversal/discuss/?currentPage=1&orderBy=most_votes&query=
+
+// submission codes start here
+
+impl Solution {
+    pub fn is_same_after_reversals(num: i32) -> bool {
+        num == 0 || num % 10 != 0
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_2119_example_1() {
+        let num = 526;
+
+        let result = true;
+
+        assert_eq!(Solution::is_same_after_reversals(num), result);
+    }
+
+    #[test]
+    fn test_2119_example_2() {
+        let num = 1800;
+
+        let result = false;
+
+        assert_eq!(Solution::is_same_after_reversals(num), result);
+    }
+
+    #[test]
+    fn test_2119_example_3() {
+        let num = 0;
+
+        let result = true;
+
+        assert_eq!(Solution::is_same_after_reversals(num), result);
+    }
+}