Create 3005-count-elements-with-maximum-frequency.java

Author: sanajitjana

Easy/3005-count-elements-with-maximum-frequency.java

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+/*
+https://leetcode.com/problems/count-elements-with-maximum-frequency/
+3005. Count Elements With Maximum Frequency
+
+You are given an array nums consisting of positive integers.
+Return the total frequencies of elements in nums such that those elements all have the maximum frequency.
+
+Example 1:
+Input: nums = [1,2,2,3,1,4]
+Output: 4
+Explanation: The elements 1 and 2 have a frequency of 2 which is the maximum frequency in the array.
+So the number of elements in the array with maximum frequency is 4.
+
+Example 2:
+Input: nums = [1,2,3,4,5]
+Output: 5
+Explanation: All elements of the array have a frequency of 1 which is the maximum.
+So the number of elements in the array with maximum frequency is 5.
+
+Constraints:
+1 <= nums.length <= 100
+1 <= nums[i] <= 100
+
+Approach:
+1. Count the frequency of each element using a HashMap.
+2. Find the maximum frequency among all elements.
+3. Sum the frequencies of elements that match this maximum.
+4. Return the result.
+
+Time Complexity: O(n)   where n = length of nums
+Space Complexity: O(k)  where k = number of distinct elements (at most 100)
+*/
+
+class Solution {
+    public int maxFrequencyElements(int[] nums) {
+        HashMap<Integer, Integer> freq = new HashMap<>();
+        
+        // Step 1: count frequencies
+        for (int num : nums) {
+            freq.put(num, freq.getOrDefault(num, 0) + 1);
+        }
+
+        // Step 2: find maximum frequency
+        int max = 0;
+        for (int val : freq.values()) {
+            max = Math.max(max, val);
+        }
+
+        // Step 3: sum up frequencies of elements with maximum frequency
+        int ans = 0;
+        for (int val : freq.values()) {
+            if (val == max) ans += val;
+        }
+
+        return ans;
+    }
+}