LeetCode 260

Single Number III

Given an array of numbers

nums

, in which exactly two elements appear only once and all the other elements appear exactly twice. Find the two elements that appear only once.

For example:

Given

nums = [1, 2, 1, 3, 2, 5]

, return

[3, 5]

.

Note:

The order of the result is not important. So in the above example,

[5, 3]

is also correct.

Your algorithm should run in linear runtime complexity. Could you implement it using only constant space complexity?

public class Solution {
public int[] singleNumber(int[] nums) {

Set<Integer> set = new HashSet<Integer>();
for(int i:nums){
if(set.add(i) == false){
set.remove(i);
}
}
int a[] = new int [set.size()];
int b = 0;
for(int c:set){
a[b] = c;
b++;
}

return a;
}
}