二分查找法(递归)

#include
#include
using namespace std;

 

int HalfSearch(const vector &a, const int& x, int low, int high)
{
 if(low > high)
  return -1;
 
 int mid = (low + high)/2;
 cout<<(char)a[mid]< if(a[mid] < x)
  return HalfSearch(a, x, mid + 1, high);
 else if(a[mid] > x)
  return HalfSearch(a, x, low, mid - 1);
 else
  return mid;
}

int Search(const vector& a, const int& x)
{
 return HalfSearch(a, x, 0, a.size() - 1);
}

 

void main()
{
 vector v;
 v.push_back('b');
 v.push_back('c');
 v.push_back('d');
 v.push_back('e');
 v.push_back('f');
 v.push_back('g');
 v.push_back('h');
 v.push_back('i');
 v.push_back('j');
 v.push_back('k');
 Search(v, 1);
}

打印结果：f c b