HELP: Trouble with partial filled arrays

Question

For HW, I have to write a deleteRepeats static method for an array of characters that deletes any character previously listed and returns the new array size. The example the problem gives is:
char a[10];
a[0]='a';
a[1]='b';
a[2]='a';
a[3]='c';
int size = 4;
size = deleteRepeats(a, size);
The problem then says after the code is executed, a[0] should be 'a', a[1] should be 'b', a[2] should be 'c' and size is 3. I read the section in my book on partially filled arrays, but I still can't get this method to work properly. Here is my code:
public static int deleteRepeats(char[] a, int size) {
size=a.length;
for(int i=0; i<size; i++) {
for(int j=1; i+j<size; j++) {
if(a==a[i+j]) {
a[i+j]=a[(i+j)+1];
size--;
return size;
With that code, when I put in the test array [aabcd], it returns 3, when it should be 4 and it changes the array to [abccd]. I'm sure there's numerous problems with my code. Any help is greatly appreciated.

Answer 1

Please post code in code tags.
First, I have no idea why they make you work with partially-filled arrays. It seems like the worst idea in the world. You should use ArrayLists for this kind of thing.
Why do you do "size=a.length;" at the beginning of the method? You lose the size information.
And I don't see how the algorithm does what you want. When you "delete" an element from your list of numbers in the array, you need to shift all later elements backwards to fill the gap.