【面试题40】数组中只出现一次的数字

 1         public static void FindNumsAppearOnce(int[] data)
 2         {
 3             if (data == null || data.Length < 1)
 4                 throw new Exception("Arraty is empty!");
 5 
 6             int numA = 0, numB = 0, numAll = 0;
 7 
 8             foreach (int num in data)
 9                 numAll ^= num;
10 
11             int bitOneFlag = GetBitOneFlag(numAll);
12 
13             foreach (int num in data)
14             {
15                 if ((num & bitOneFlag) == 1)
16                     numA ^= num;
17                 else
18                     numB ^= num;
19             }
20 
21             Console.WriteLine("numA:{0},numB:{1}", numA, numB);
22         }
23 
24         public static int GetBitOneFlag(int num)
25         {
26             int count = 0;
27 
28             while ((num & 1 << count) == 0)
29                 count++;
30 
31             return 1 << count;
32         }