折半查找函数模板举例

初始化int类型数组data1={1,3,5,7,9,11,13,15,17,19,2,4,6,8,10,12,14,16,18,20}，提示用户输入一个数字，应用折半查找函数模板找出它的位置。

#include
using namespace std;

template
int BinSearch(T list[],int n,T key)
{
   int mid,low,high;
   T midvalue;
   low=0;
   high=n-1;
   while(low<=high)
   {
     mid=(low+high)/2;
     midvalue=list[mid];
     if(key==midvalue)
       return mid;
     else if(key>midvalue)
       low=mid+1;
     else
       high=mid-1;
   } 
   return -1; 
}
int main()
{
  int key,mid,n=20;
  int data1[]={1,3,5,7,9,11,13,15,17,19,2,4,6,8,10,12,14,16,18,20};
  cout<<"Please input a key:"<  cin>>key;
  cout<}