Question

So, I’m trying to tally the elements of an array. By this I mean, I have a large array, and each element will have multiples of itself throughout the array. I am trying to figure out how many times each element occurs, however I keep running into the issue of there being duplicate tallies. Since “x” could exist at 12 different places in the array, when I loop through it and keep a running sum, I get the tally for “x” 12 different times. Does anyone know of a simpler/better way to keep a tally of an array with no duplicates?

My code is:

where count is the number of elements

    for(i=0;i<count;i++)
    {


            for(x=0; x<count;x++)
            {
                    if(array[i]==array[x])
                    {
                            tallyz++;
                    }   

            }

                    tally[i]=tallyz-1;
                    tallyz=0;
                    }

    }

Answer 1

If you can sort the array, simply sort it. Then all you have left is a linear scan of the elements, checking if the element behind this one is the same as the current element (don’t forget bounds checking).