数字在排序数组中出现的次数

题目描述

统计一个数字在排序数组中出现的次数。
 1 class Solution {
 2 public:
 3     int GetNumberOfK(vector<int> data ,int k) {
 4         int len= data.size();
 5         if (len == 0)
 6             return 0;
 7         bool find = 0;
 8         int begin = 0,end = len -1,mid;
 9         while(begin <= end)
10         {
11             mid = (begin + end)/2;
12             if(data[mid] > k)
13             {
14                 end = mid - 1;
15             }
16             else if(data[mid] < k)
17             {
18                 begin = mid + 1;
19             }
20             else
21             {
22                 find = 1;
23                 break;
24             }
25         }
26         if(!find)
27             return 0;
28         
29         int cnt = 1;
30         int i = mid + 1;
31         while(i < len && data[i] == k)
32         {
33             ++ cnt;
34             ++i;
35         }
36         i = mid - 1;
37         while(i >=0 && data[i] == k)
38         {
39             ++ cnt;
40             --i;
41         }
42         return cnt;
43     }
44 };