remove duplicate characters from a sorted string

void removeDup(int a[], int& len)
{
int j=1;
for(int i=0, k=1; i< len && k< len; i++, k++)
{
//cout << a[i] << " " ;
if(a[i] != a[k])
{
a[j] = a[k];
j++;
}
}

len =j;
}