Majority element done

Author: rampatra

src/main/java/com/leetcode/arrays/MajorityElement.java

@@ -0,0 +1,47 @@
+package com.leetcode.arrays;
+
+/**
+ * Level: Easy
+ * Problem Link: https://leetcode.com/problems/majority-element/
+ * Problem Description:
+ * 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.
+ *
+ * @author rampatra
+ * @since 2019-04-27
+ */
+public class MajorityElement {
+
+    /**
+     * Time complexity: O(n)
+     * Runtime: <a href="https://leetcode.com/submissions/detail/225284632/">1 ms</a>.
+     *
+     * @param nums
+     * @return
+     */
+    public static int majorityElement(int[] nums) {
+        int count = 0;
+        int majElem = nums[0];
+
+        for (int i = 0; i < nums.length; i++) {
+            if (count <= 0) {
+                majElem = nums[i];
+                count = 0;
+            }
+            if (majElem == nums[i]) {
+                count++;
+            } else {
+                count--;
+            }
+        }
+
+        return majElem;
+    }
+
+    public static void main(String[] args) {
+        System.out.println(majorityElement(new int[]{10, 9, 9, 9, 10}));
+        System.out.println(majorityElement(new int[]{2, 3, 2, 2, 3, 2}));
+        System.out.println(majorityElement(new int[]{2, 3, 2, 2, 2, 3}));
+    }
+}