1663. Smallest String With A Given Numeric Value: AC

Author: tan-wei

src/solution/mod.rs

@@ -1253,3 +1253,4 @@ mod s1657_determine_if_two_strings_are_close;
 mod s1658_minimum_operations_to_reduce_x_to_zero;
 mod s1659_maximize_grid_happiness;
 mod s1662_check_if_two_string_arrays_are_equivalent;
+mod s1663_smallest_string_with_a_given_numeric_value;

src/solution/s1663_smallest_string_with_a_given_numeric_value.rs

@@ -0,0 +1,74 @@
+/**
+ * [1663] Smallest String With A Given Numeric Value
+ *
+ * The numeric value of a lowercase character is defined as its position (1-indexed) in the alphabet, so the numeric value of a is 1, the numeric value of b is 2, the numeric value of c is 3, and so on.
+ * The numeric value of a string consisting of lowercase characters is defined as the sum of its characters' numeric values. For example, the numeric value of the string "abe" is equal to 1 + 2 + 5 = 8.
+ * You are given two integers n and k. Return the lexicographically smallest string with length equal to n and numeric value equal to k.
+ * Note that a string x is lexicographically smaller than string y if x comes before y in dictionary order, that is, either x is a prefix of y, or if i is the first position such that x[i] != y[i], then x[i] comes before y[i] in alphabetic order.
+ *  
+ * Example 1:
+ *
+ * Input: n = 3, k = 27
+ * Output: "aay"
+ * Explanation: The numeric value of the string is 1 + 1 + 25 = 27, and it is the smallest string with such a value and length equal to 3.
+ *
+ * Example 2:
+ *
+ * Input: n = 5, k = 73
+ * Output: "aaszz"
+ *
+ *  
+ * Constraints:
+ *
+ * 	1 <= n <= 10^5
+ * 	n <= k <= 26 * n
+ *
+ */
+pub struct Solution {}
+
+// problem: https://leetcode.com/problems/smallest-string-with-a-given-numeric-value/
+// discuss: https://leetcode.com/problems/smallest-string-with-a-given-numeric-value/discuss/?currentPage=1&orderBy=most_votes&query=
+
+// submission codes start here
+
+impl Solution {
+    pub fn get_smallest_string(n: i32, k: i32) -> String {
+        let mut result: Vec<char> = vec!['a'; n as usize];
+        let mut idx: usize = n as usize - 1;
+        let mut value = k - n;
+        while value > 25 {
+            result[idx] = 'z';
+            idx -= 1;
+            value -= 25;
+        }
+        result[idx] = (value as u8 + 'a' as u8) as char;
+        result.into_iter().collect::<String>()
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_1663_example_1() {
+        let n = 3;
+        let k = 27;
+
+        let result = "aay".to_string();
+
+        assert_eq!(Solution::get_smallest_string(n, k), result);
+    }
+
+    #[test]
+    fn test_1663_example_2() {
+        let n = 5;
+        let k = 73;
+
+        let result = "aaszz".to_string();
+
+        assert_eq!(Solution::get_smallest_string(n, k), result);
+    }
+}