給出2*n + 2個的數字，除其中兩個數字之外其他每個數字均出現兩次，找到這兩個數字。

dalao解法：

public List<Integer> singleNumberIII(int[] A) {
    // write your code here
    //https://blog.csdn.net/wutingyehe/article/details/51085309?utm_source=copy
    if(null == A || A.length ==0) return null;
    List<Integer> list = new ArrayList<Integer>();
    int x = 0;
    for(int i = 0; i < A.length; i++) {
        x ^= A[i];
    }
    int k = 0;
    while((x % 2) == 0 && k < 32){
        k++;
        x>>=1;
    }
    int result1 = 0, result2 = 0;
    for(int i = 0; i < A.length; i++) {
        if(((A[i]>>>k) & 1) == 0) {
            result1 ^= A[i];
        }else {
            result2 ^= A[i];
        }
    }
    list.add(result1);
    list.add(result2);
    return list;

}
 

有點像分而治之