Question

public void removeDups() {
    int i, k, j, lastFound = 0;
    if (this.nElements < 1) {
        System.out.println("Empty Array");

    } else {


        for (i = 0; i < this.nElements; i = lastFound) //outer loop
            {


            for (j = i + 1; j < this.nElements; j++) {

                 if (this.arr[i] == this.arr[j]) {
                    lastFound = i;

                    for (k = i; k < this.nElements; k++) {
                        this.arr[k] = this.arr[k + 1];


                    }
                    this.nElements--;

                    break;
                }
            }




        }
        for (i = 0; i < this.nElements; i++) {
            System.out.println(this.arr[i]);

        }




    }

}

the previous method removes duplicates from the object invoking it (Array),the problem is that i want the outer loop to begin from a certain position every increment, i assign the value of that position to the variable lastFound and put that variable in the incremental part of the loop but the program goes to infinite loop and never stops, what is the problem with that?

Answer 1

You’re setting i = lastFound at every iteration. At the start of the outer loop, initialize lastFound to i + 1. That way it will increment normally if you don’t reset lastFound.

Alternatively, get rid of lastFound and when you find a match, set i = i - 1, start the k loop at i + 1 instead of i, and change the increment expression in the outer loop from i = lastFound to i++. I would also simplify your code by using System.arraycopy:

public void removeDups() {
    if (nElements < 1) {
        System.out.println("Empty Array");
    } else {
        for (int i = 0; i < nElements; i++) {
            for (int j = i + 1; j < nElements; j++) {
                 if (arr[i] == arr[j]) {
                    System.arraycopy(arr, i + 1, arr, i, nElements - (i + 1));
                    nElements--;
                    i--;
                    break;
                }
            }
        }
        for (i = 0; i < nElements; i++) {
            System.out.println(arr[i]);
        }
    }
}