top-k-frequent-elements

Author: hjeomdev

top-k-frequent-elements/hjeomdev.java

@@ -0,0 +1,18 @@
+class Solution {
+    public int[] topKFrequent(int[] nums, int k) {
+        Map<Integer, Integer> map = new HashMap<>();
+
+        for (int num : nums) {
+            int current = map.getOrDefault(num, 0);
+            map.put(num, current + 1);
+        }
+
+        List<Integer> keySet = new ArrayList<>(map.keySet());
+        keySet.sort((o1, o2) -> map.get(o2).compareTo(map.get(o1)));
+
+        return keySet.subList(0, k)
+                .stream()
+                .mapToInt(Integer::intValue)
+                .toArray();
+    }
+}