C++二分查找在搜索引擎多文档求交的应用分析

int search2(int array[], int n, int v)
{
  int left, right, middle;
  left = 0, right = n - 1;
  while (left <= right)
  {
    middle = (left + right) / 2;
    if (array[middle] > v)
    {
      right = middle - 1;
    }
    else if (array[middle] < v)
    {
      left = middle + 1;
    }
    else
    {
      return middle;
    }
  }
  return -1;
}
int search3(int array[], int n, int v)
{
  int left, right, middle;
  left = 0, right = n;
  while (left < right)
  {
    middle = (left + right) / 2;
    if (array[middle] > v)
    {
      right = middle;
    }
    else if (array[middle] < v)
    {
      left = middle + 1;
    }
    else
    {
      return middle;
    }
  }
  return -1;
}