Find the top N of a given integer array. Complexity = O (n.log(k)). I needed to show top 10 data and there was too much data. Brute force wasn't a solution because getting report was slow. I made it as fast as possible. PriorityQueue was a big help because of getting data complexity is O (log(k)). I also made it a general method, thus everyone c…

gistfile1.java

private static void findTopN(int[] a, int k) {
   if (a == null) return;
   if (a.length <= k) {
      return;
   }
   PriorityQueue<Integer> pq = new PriorityQueue<Integer> (k);
   for (int i = 0; i < a.length; i++) {
      pq.add(a[i]);
      if (pq.size() > k) {
         pq.poll();
      }
   }
   while (!pq.isEmpty()) {
      System.out.print(pq.poll() + " ");
   }
}