Simple socket

#include <iostream> 
#include <fstream> 
#include <string>
#include <vector>
#include <conio.h>
#include <cstdlib>
#include <ctime>
using namespace std;
int main () 
{ 

  char*ten=new char[100];
	string *thongtin=new string[100];
	string line;
	int *a=new int[100];
	ifstream myfile ("data.txt"); 
	int i=1;
	int dongcauhoi;
	int slch,goicauhoi;
	int demdong;
	int diem=0;
	int socau;
	if (myfile.is_open()) 
	{ 
		while (! myfile.eof() ) 
		{ 
			getline (myfile,line); 
			thongtin[i]=line;
			i++;
		} 
		demdong=i;
		myfile.close(); 
	} 
	else cout << "Unable to open file"; 
	cout<<"-------------Chao mug cac ban den voi tro choi van hoc--------------"<<endl;
	cout<< "\t\t  moi ban nhap so luong cau hoi de choi  :";
	srand(time(0));
	cin>>slch;
	socau=slch;

	do {
		int goicauhoi=(rand()%(slch+1)) +1;
		cout<<endl;
		for(int j=goicauhoi-1;j<demdong;j++)
		{

				dongcauhoi=1+3*j;
				break;
			
		}
		for(int i=dongcauhoi;i<=demdong;i++)
		{
			cout<<"cau hoi "<<thongtin[i]<<thongtin[i+1]<<endl;
			cout<<"\t nhap cau tra loi  :";
			fflush(stdin);
			gets(ten);
			cout<<"\t Dap An :"<<thongtin[i+2]<<endl;
			if(thongtin[i+2]==ten)
			{
				diem++;
				cout<<"ban chon dung:"<<endl;
			}
			break;
		}
		slch--;
	}while(slch>0);

	if(diem==socau)
	{
		cout<<"\t------good-----win-------";
	}
	return 0;
	getch();
}