基础...二分搜索

template <class T>
int binarySearch(const T list[],const T &x,int n)
{
int left = 0,right = n-1;
int middle;
while(left<right)
{
middle = (left+right)/2;
if(x == list[middle])
{
cout<<x<<"在第"<<middle+1<<"个位置"<<endl;;
return 0;
}
else if(x >list[middle])
{
left = middle+1;
}
else if(x<list[middle])
{
right = middle-1;
}
}
cout<<"未找到"<<endl;
return 1;

}