一维变长数组

template<class T>
void changeLength1D(T*& a,int oldLength,int newLength)
{
	if(newLength >= 0)
	{
		T* temp = new T[newLength];
		int number = min(oldLength,newLength);//确定要复制元素个数
		copy(a,a+number,temp);
		delete [] a;//释放老数组空间
		a = temp;
	}
	else
	{
		cout<<"数组长度应该大于0"<<endl;
	}
}