Remove Element

Given an array and a value, remove all instances of that value in place and return the new length.

The order of elements can be changed. It doesn't matter what you leave beyond the new length.

Use a count to track all elements which are different than elem itself.

public int removeElement(int[] A, int elem) {
        if (A==null||A.length==0) {
            return 0;
        }

        int count = 0;
        for (int i=0; i<A.length; i++) {
            if (A[i] != elem) {
                A[count] = A[i];
                count = count+1;
            }
        }
        return count;
    }