Create 347TopKFrequentElements..java

bala2it4u · web-flow · commit 9fd2c6561d65 · 2022-04-08T17:04:58.000+05:30
diff --git a/java/347TopKFrequentElements..java b/java/347TopKFrequentElements..java
@@ -0,0 +1,40 @@
+class Solution {
+    public int[] topKFrequent(int[] nums, int k) {
+        //hashmap, check count == k, add to result
+        //List<Integer> result = new ArrayList();
+        HashMap<Integer, Integer> map = new HashMap();
+        //int max = 0;
+        
+        for (int idx=0;idx<nums.length;idx++){
+            int num = nums[idx];
+            
+            map.put(num, map.getOrDefault(num,0)+1);
+            
+            //max = Math.max(max, map.get(num));
+        }
+        List<Integer> set = new ArrayList<Integer>(map.keySet());
+        List<Integer>[] out = new List[nums.length+1];
+        
+        for (int idx=0;idx<set.size();idx++){
+            int count = map.get(set.get(idx));
+            
+            //if (count )
+            if (out[count] == null)out[count] = new ArrayList<Integer>();
+            
+            out[count].add(set.get(idx));
+        }
+        
+        int[] result = new int[k];
+        int i=0;
+        for (int idx=out.length-1;i<k;idx--) {
+            if (out[idx] == null) continue;
+        
+            for (Integer temp : out[idx]){
+                if (i>=k) break;
+                
+                result[i++]= temp;
+            }
+        }
+        return result;
+    }
+}
