Added majority element solution.

README.md

@@ -157,6 +157,7 @@ programming challenges completed in other languages.
 - [Final Value of Variable After Operations](https://leetcode.com/problems/final-value-of-variable-after-performing-operations/)
 - [Substring With Distinct Characters](https://leetcode.com/problems/substrings-of-size-three-with-distinct-characters/)
 - [Remove Element](https://leetcode.com/problems/remove-element)
+- [Majority Element](https://leetcode.com/problems/majority-element)
 
 #### Medium
 

src/codewars/majority_element.rs

@@ -0,0 +1,19 @@
+use std::collections::HashMap;
+
+pub fn majority_element(numbers: Vec<i32>) -> i32 {
+    let freq = numbers.into_iter().fold(HashMap::new(), |mut acc, curr| {
+        *acc.entry(curr).or_insert(0) += 1;
+        acc
+    });
+    freq.into_iter().max_by_key(|e| e.1).unwrap().0
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn calculates_majority_element() {
+        assert_eq!(2, majority_element(vec![1, 2, 2, 1, 2]))
+    }
+}

src/codewars/mod.rs

@@ -21,6 +21,8 @@ mod first_non_consecutive;
 mod frequency_sort;
 mod gps;
 mod josephus;
+mod lazy_repeater;
+mod majority_element;
 mod max_profit;
 mod multiplication;
 mod multiplication_table;
@@ -29,6 +31,7 @@ mod nearest_prime;
 mod not_secure;
 mod nth_power;
 mod order;
+mod parse_number;
 mod pascal_case;
 mod people_on_the_bus;
 mod perimeter;
@@ -43,10 +46,8 @@ mod sort_numbers;
 mod spinning_words;
 mod square;
 mod stocks;
+mod sum_digits_power;
 mod summation;
 mod sumpairs;
 mod valid_parentheses;
 mod valid_spacing;
-mod lazy_repeater;
-mod parse_number;
-mod sum_digits_power;