CODE

public class Solution {
  public int[] DailyTemperatures(int[] temperatures) {

    List<int> stack1 = new List<int>();
    List<int> stack2 = new List<int>();

    int[] result = new int[temperatures.Length];

    for (int i = temperatures.Length-1; i >= 0; i--)
      stack1.Insert(0, temperatures[i]);

    int r = 0;
    while(stack1.Count > 0)
    {
      int j = 0;

      int curr = 0;           
      stack2.Insert(0, stack1[0]);
      stack1.RemoveAt(0);

      while (stack1.Count > 0 && stack1[0] <= stack2[curr])
      {
        stack2.Insert(0, stack1[0]);
        stack1.RemoveAt(0);       
        curr++;
      }

      /* last item - no future days, set to 0 */
      if (stack1.Count < 1 && stack2.Count == 1)
      {
        result[r] = 0;
      }

      /* no more numbers on stack 1 > current temp, result for this one is 0 */
      else if (stack1.Count < 1 && stack2[0] <= stack2[curr])
      {
        result[r] = 0;
      }
      else
      {
        stack2.Insert(0, stack1[0]);
        stack1.RemoveAt(0);
        curr++;
        result[r] = curr;                           
      }    

      while (j != curr)
      {
        stack1.Insert(0, stack2[0]);
        stack2.RemoveAt(0);
        j++;
      }
      stack2.RemoveAt(0);
      r++;
    }   
    return result;
  }
}