260. Single Number III

　　问题：　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].

　　解决：新技能get!  位运算的巧妙使用，特性：任何数字异或自身都为0

　　代码:

　　

package com.wang.test;
 
import javax.naming.ldap.SortControl;

/*
 * @tittle:260. Single Number III
 * @author:wwwglin
 * @time:2016/04/18
 */
public class SingleNumberIII {
    //任何数字异或自身都为0
    public int[] singleNumber(int[] nums) {
        int resTwo = 0;
        int[] res = new int[2];
        for (int i = 0; i < nums.length; i++) {
            resTwo ^= nums[i];
        }
        // find the rigthest bit which is not 0
        resTwo &= -resTwo;
        for (int i = 0; i < nums.length; i++) {
            if ((nums[i] & resTwo) == 0) {
                res[0] ^= nums[i];
            } else {
                res[1] ^= nums[i];
            }
        }
        return res;
    }

    public static void main(String[] args) {
        int[] nums = { 1, 2, 3, 5, 7, 2, 4, 1, 7, 5 };
        int[] res = new SingleNumberIII().singleNumber(nums);
        for (int i : res) {
            System.out.println(i);
        }
        
    }
}