题解 | #数字在升序数组中出现的次数#

/**
 * 
 * @param data int整型一维数组 
 * @param dataLen int data数组长度
 * @param k int整型 
 * @return int整型
 */
int GetNumberOfK(int* data, int dataLen, int k )
{
    int left = 0;
    int right = dataLen - 1;
    int mid = 0;
    int num = 0;
    int flag = 0;
    while(left <= right)
    {
        if(k>data[right])
            break;
        mid = left + (right - left) / 2;
        if(data[mid] > k)
        {
            right = mid - 1;
        }
        else if(data[mid] < k) 
        {
            left = mid + 1;
        }
        else 
        {
            flag = mid - 1;
            while(data[flag]==k && flag >= 0)
            {
                ++num;
                flag--;
            }
            while (data[mid]==k && mid < dataLen) 
            {
                ++num;
                mid++;
            }
            break;
        }
    }
    return num;
    // write code here
}