CODE

public class Solution {
  public int LastStoneWeight(int[] stones) {
    int marker = 0;
    Array.Sort(stones);
    Array.Reverse(stones);

    List<int> pQueue = new List<int>();

    for (int i = 0; i < stones.Length; i++)
      pQueue.Add(stones[i]);

    while (pQueue.Count - marker > 1)
    {
      int x = pQueue[marker++];
      int y = pQueue[marker++];
      if (y < x)
      {
        int newWeight = x - y;
        if (marker == pQueue.Count)
          pQueue.Add(newWeight);
        else
        {
          int range = pQueue.Count + 1;
          for (int i = marker; i < range; i++)
          {
            if (i == pQueue.Count)
              pQueue.Add(newWeight);
            else
            if (pQueue[i] <= newWeight)
            {
              pQueue.Insert(i, newWeight);
              break;
            }
          }
        }
      }
    }
    if (marker >= pQueue.Count)
      return 0;
    return pQueue[marker];
  }
}