练习1.11：打印出两个整数之间的所有数

#include <iostream>
using namespace std;
int main()
{
	int n1,n2 = 0;
	cout << "Input two numbers please:"<<endl;
	cin>> n1 >> n2;
	if (n1<n2)
	{
		cout << "The numbers between "<<n1<<" and "<<n2<<" are: ";
		int n = 0;
		int num = n2 - n1 -1;
		while( n < num )
		{    
			++n1;
			cout <<" "<< n1;	
			++n;
		}
	}
	else if(n1>n2)
	{
		cout << "The numbers between "<<n2<<" and "<<n1<<" are: ";
		int n = 0;
		int num = n1 -n2 -1;  //为什么while(n < n1 - n2 -1)时不能打印出正确的结果，优先级的问题？
		while(n< num )
		{
			--n1;
			cout <<" "<< n1; 
			++n;
		}
	}
	return 0;
}