2.5

#include<iostream>
#include<fstream>
#include<string>
#include<vector>
using namespace std;
int main()
{
	vector<string> v;
	ifstream in("2_5txt.txt");
	string line;
	while(getline(in,line)){
		v.push_back(line);
	}
	for(int i = v.size()-1;i >= 0;i--)
		cout << i << " : " << v[i] << endl;
		
	cin.get();
}

txt

Tsinghua is the best
I'm the best
hhh
mabaoguo

the young man bujiangwude
qu tou

touxi
wo

69sui de laotongzhi