Find the missing and duplicate elements in an array in linear time and constant space

Question

You’re given an array of N 64 bit integers. N may be very large. You know that every integer 1..N appears once in the array, except there is one integer mis

Answer 1

Here is a Java implementation based on @Aryabhatta 's idea:
Input:[3 1 2 5 3]
Output:[3, 4]

public ArrayList repeatedNumber(final List A) {
    ArrayList ret = new ArrayList<>();
    int xor = 0, x = 0, y = 0;
    for(int i=0; i