20250608 finished.

src/problem/mod.rs

@@ -698,3 +698,5 @@ mod p1061_lexicographically_smallest_equivalent_string;
 mod p2434_using_a_robot_to_print_the_lexicographically_smallest_string;
 
 mod p3170_lexicographically_minimum_string_after_removing_stars;
+
+mod p386_lexicographical_numbers;

src/problem/p386_lexicographical_numbers.rs

@@ -0,0 +1,50 @@
+/**
+ * [386] Lexicographical Numbers
+ */
+pub struct Solution {}
+
+// submission codes start here
+
+impl Solution {
+    pub fn lexical_order(n: i32) -> Vec<i32> {
+        let mut result = Vec::with_capacity(n as usize);
+
+        for i in 1..10 {
+            Self::search(&mut result, i, n);
+        }
+
+        result
+    }
+
+    fn search(result: &mut Vec<i32>, mut prefix: i32, n: i32) {
+        if prefix <= n {
+            result.push(prefix);
+        }
+
+        prefix = prefix * 10;
+
+        for i in 0..10 {
+            if prefix + i > n {
+                break;
+            }
+
+            Self::search(result, prefix + i, n);
+        }
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_386() {
+        assert_eq!(vec![1, 2], Solution::lexical_order(2));
+        assert_eq!(
+            vec![1, 10, 11, 12, 13, 2, 3, 4, 5, 6, 7, 8, 9],
+            Solution::lexical_order(13)
+        );
+    }
+}