Finding maximum sub array in a given array

Hello everybody ,

I have got this question from some website and felt i should put it in my blog under a new label "interview section " 

As the question speaks out , we need to find out the maximum number of a sub array in a given array  ( this sub array was containing positive and negative integers so the question makes sense).

to make it more clear , assume we have an array 

example 1 :

 {3,4,-1,0,8,3,4,10,32,-30,5}        in this array the maximum sub array would be "57"

example 2 :

{3,4,-1,0,8,3,4,-20,32,-30,5};    in this array the maximum sub array would be "32" .

So we will try to write the program in a simplest form and with less complexity !

void main()
{
  int i = 0;
  int prev_max  = 0;
  int new_max  = 0;
  for (i = 0 ;i < 30; i ++)
   {
     new_max  += array[i];
      if(new_max < 0 )
          new_max = 0;
      else
        {
          if(prev_max < new_max)
          prev_max = new_max;
        }
   }

printf("Max of a sub array is %d \n", prev_max);


}

Above logic would find out the maximum of a sub array with o(n) complexity . 

I shall come up with such simple yet interesting questions on a regular basis.