lintcode->落单的数

package 落单的数;public class Solution {    public int singleNumber(int[] A) {        // Write your code here        int ans = 0;        for(int i:A){            ans ^= i;        }        return ans;    }    public static void main(String[] args) {        int[] A = {1,2,3,1,2};        System.out.println(new Solution().singleNumber(A));    }}