function to split and rearrange array

[dhv]

Hi, this is actually for a homework project, so I'm looking for some guidance. I need to write a function that will take in an array and split the function, rearranging the array by putting any elements < splitter before the splitter string and elements > splitter after it. The arguments must remain the way they are. The function works for the most part, except when the splitter string appears more than once in the array.

string f[6] = { "grant", "buster", "kari", "tory", "adam", "jamie" };
int r = split(f, 6, "jessi");  //  returns 4
	// f might now be
	//	"grant"  "buster"  "jamie"  "adam"  "tory"  "kari"
	// or   "jamie"  "adam"  "buster"  "grant"  "kari"  "tory"
	// or one of several other orderings.
	// The first 4 elements are < "jessi"; the last 2 aren't.
string g[4] = { "jamie", "adam", "buster", "narrator" };
int s = split(g, 4, "buster");  //  returns 1
	// g must now be either
	//	"adam"  "buster"  "narrator"  "jamie"
	// or	"adam"  "buster"  "jamie"  "narrator"
	// All elements < "buster" (i.e., "adam") come before all others.
	// All elements > "buster" (i.e., "jamie" and "narrator") come
	//      after all others. 

This is what I have so far:

int split(string a[], int n, string splitter)
{
	if(n < 0)
		return -1;
	int i = 0;
	int j = n-1;
	string swap;
	while(i < j)
	{
		if(a[i] >= splitter)
		{
			swap = a[j];
			a[j] = a[i];
			a[i] = swap;
		}
		if(a[i] < splitter)
			i++;
		if(a[j] > splitter)
			j--;
	}
	if(j == n-1)
		return n;
	return i;
}