solves majority element in java

Author: anishLearnsToCode

src/MajorityElement.java

@@ -1,24 +1,20 @@
-import java.util.HashMap;
-import java.util.Map;
+// https://leetcode.com/problems/majority-element
+// T: O(N)
+// S: O(1)
 
 public class MajorityElement {
-    public int majorityElement(int[] array) {
-        Map<Integer, Integer> frequencies = getFrequencies(array);
-        int maxFrequency = frequencies.values().stream().max(Integer::compareTo).get();
-        for (Map.Entry<Integer, Integer> entry : frequencies.entrySet()) {
-            if (entry.getValue() == maxFrequency) {
-                return entry.getKey();
-            }
-        }
+    public int majorityElement(int[] nums) {
+        int candidate = nums[0], frequency = 0;
 
-        return -1;
-    }
+        for (int element : nums) {
+            frequency += element == candidate ? 1 : -1;
 
-    private static Map<Integer, Integer> getFrequencies(int[] array) {
-        Map<Integer, Integer> result = new HashMap<>();
-        for (int element : array) {
-            result.put(element, result.getOrDefault(element, 0) + 1);
+            if (frequency == 0) {
+                candidate = element;
+                frequency = 1;
+            }
         }
-        return result;
+
+        return candidate;
     }
 }