added Majority Element (easy)

Author: minhyeong-joe

Easy/MajorityElement/README.md

@@ -0,0 +1,20 @@
+
+# Majority Element
+[Leetcode Link](https://leetcode.com/problems/majority-element/)
+
+## Problem:
+
+Given an array of size `n`, find the majority element. The majority element is the element that appears **more than** `⌊ n/2 ⌋` times.
+
+You may assume that the array is non-empty and the majority element always exist in the array.
+
+## Example:
+
+```
+Input: [3,2,3]
+Output: 3
+```
+```
+Input: [2,2,1,1,1,2,2]
+Output: 2
+```

Easy/MajorityElement/solution.py

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+from typing import List
+import math
+
+
+def majorityElement(nums: List[int]) -> int:
+ numCounter = dict()
+ for num in nums:
+ numCounter[num] = numCounter.get(num, 0) + 1
+ for k, v in numCounter.items():
+ if v > math.floor(len(nums)/2):
+ return k
+ return None
+
+
+# test driver
+input = [3, 2, 3]
+print("Input:", input)
+print("Output:", majorityElement(input))
+print()
+
+input = [2, 2, 1, 1, 1, 2, 2]
+print("Input:", input)
+print("Output:", majorityElement(input))
+print()

README.md

@@ -25,6 +25,7 @@ Languages used: Java and Python
  - [Maximum Product of Three Numbers](Easy/MaxProductofThreeNumbers)
  - [Maximize Sum Of Array After K Negations](Easy/MaximizeSumAfterKNegations)
  - [House Robber](Easy/HouseRobber)
+ - [Majority Element](Easy/MajorityElement)
 - Medium
  - [Minimum Add to Make Parentheses Valid](Medium/MinimumAddtoMakeParenthesesValid)
  - [Distribute Coins in Binary Tree](Medium/DistributionCoinsInBinaryTree)