Merge pull request #3002 from aestheticw3/patch-5

Update 0169-majority-element.js

Author: sujal-goswami

javascript/0169-majority-element.js

@@ -1,20 +1,47 @@
-//  problem link https://leetcode.com/problems/majority-element
-// time complexity O(n)
+/**
+ * Boyer Moore Algorithm
+ * Time O(N) | Space O(1)
+ * https://leetcode.com/problems/majority-element
+ * @param {number[]} nums
+ * @return {number}
+ */
 
-var majorityElement = function(nums) {
-    
-    const occuranceOfElement = new Map();
-    for(let i = 0; i < nums.length; i++) {
-        if(occuranceOfElement.has(nums[i])) {
-            let occurance = occuranceOfElement.get(nums[i]);
-            occuranceOfElement.set(nums[i], occurance+1);
-        } else {
-            occuranceOfElement.set(nums[i], 1);
-        }
-    }
+var majorityElement = function (nums) {
+	let res = nums[0];
+	let count = 1;
 
-    for(let [key,value] of occuranceOfElement) {
-        if(value > nums.length / 2) return key;
-    }
+	for (let i = 1; i < nums.length - 1; i++) {
+		if (nums[i] === res) count++;
+		else if (!--count) {
+			res = nums[i + 1];
+			count = 0;
+		}
+	}
 
+	return res;
+};
+
+/**
+ * HashMap
+ * Time O(N) | Space O(N)
+ * https://leetcode.com/problems/majority-element
+ * @param {number[]} nums
+ * @return {number}
+ */
+
+var majorityElement = function (nums) {
+	const occuranceOfElement = new Map();
+	
+	for (let i = 0; i < nums.length; i++) {
+		if (occuranceOfElement.has(nums[i])) {
+			let occurance = occuranceOfElement.get(nums[i]);
+			occuranceOfElement.set(nums[i], occurance + 1);
+		} else {
+			occuranceOfElement.set(nums[i], 1);
+		}
+	}
+
+	for (let [key, value] of occuranceOfElement) {
+		if (value > nums.length / 2) return key;
+	}
 };