查找算法——二分法查找

       二分法查找是在有序线性表查找指定的元素

int BinarySort(int n)
{
   int low,high,mid;
   low = 0;
   high = length -1;
   while (low <= high)
   {
       mid = (low+high) / 2;
       if (n == m_num[mid])    return mid;
       if (n < m_num[mid])      high = mid - 1;
       else                              low = mid + 1;

   }
       return -1;
}