chore: add the rest of the local code

Signed-off-by: Matej Focko <mfocko@redhat.com>

problems/rs/time-needed-to-inform-all-employees.rs

@@ -1,5 +1,6 @@
 use std::collections::{HashMap, HashSet, VecDeque};
 
+struct Solution {}
 impl Solution {
     fn from_managers(managers: &[i32]) -> HashMap<usize, HashSet<usize>> {
         let mut mapping = HashMap::new();
@@ -35,3 +36,43 @@ impl Solution {
         minutes
     }
 }
+
+fn main() {}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    // Input: n = 1, headID = 0, manager = [-1], informTime = [0]
+    // Output: 0
+    // Explanation: The head of the company is the only employee in the company.
+    #[test]
+    fn example_1() {
+        assert_eq!(Solution::num_of_minutes(1, 0, vec![-1], vec![0]), 0);
+    }
+
+    // Input: n = 6, headID = 2, manager = [2,2,-1,2,2,2], informTime = [0,0,1,0,0,0]
+    // Output: 1
+    // Explanation: The head of the company with id = 2 is the direct manager of all the employees in the company and needs 1 minute to inform them all.
+    // The tree structure of the employees in the company is shown.
+    #[test]
+    fn example_2() {
+        assert_eq!(
+            Solution::num_of_minutes(6, 2, vec![2, 2, -1, 2, 2, 2], vec![0, 0, 1, 0, 0, 0]),
+            1
+        );
+    }
+
+    #[test]
+    fn regression_1() {
+        assert_eq!(
+            Solution::num_of_minutes(
+                15,
+                0,
+                vec![-1, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6],
+                vec![1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0]
+            ),
+            3
+        );
+    }
+}