Add problem 1689: Partitioning Into Minimum Number Of Deci-Binary Num…

…bers

src/lib.rs

@@ -1335,6 +1335,7 @@ pub mod problem_1678_goal_parser_interpretation;
 pub mod problem_1679_max_number_of_k_sum_pairs;
 pub mod problem_1684_count_the_number_of_consistent_strings;
 pub mod problem_1688_count_of_matches_in_tournament;
+pub mod problem_1689_partitioning_into_minimum_number_of_deci_binary_numbers;
 pub mod problem_1695_maximum_erasure_value;
 pub mod problem_1700_number_of_students_unable_to_eat_lunch;
 pub mod problem_1701_average_waiting_time;

src/problem_1689_partitioning_into_minimum_number_of_deci_binary_numbers/greedy.rs

@@ -0,0 +1,37 @@
+pub struct Solution;
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl Solution {
+    pub fn min_partitions(n: String) -> i32 {
+        let mut result = b'0';
+
+        for c in n.bytes() {
+            if c > result {
+                result = c;
+
+                if result == b'9' {
+                    break;
+                }
+            }
+        }
+
+        i32::from(result - b'0')
+    }
+}
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl super::Solution for Solution {
+    fn min_partitions(n: String) -> i32 {
+        Self::min_partitions(n)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}

src/problem_1689_partitioning_into_minimum_number_of_deci_binary_numbers/mod.rs

@@ -0,0 +1,18 @@
+pub mod greedy;
+
+pub trait Solution {
+    fn min_partitions(n: String) -> i32;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [("32", 3), ("82734", 8), ("27346209830709182346", 9)];
+
+        for (n, expected) in test_cases {
+            assert_eq!(S::min_partitions(n.to_string()), expected);
+        }
+    }
+}