Triangle using Do While Loop in C++

#include<iostream.h>
#include<conio.h>
void main()
{
int val;
int a = 0;
do //executing process.
{
cout<<"Please Enter Password: ";
cin>>val; //user enter value storing in 'val'.
if(val == 12345) //if 'val' value equal to 12345 then
{
cout<<"Password Correct!";
break; //break the statement.
}
else //if not then
{
cout<<"Password Invalid!"<<endl; //print this.
}
a++; //adding 1 to 'a' value.
}
while(a < 3); //loop looping and checking condition.
getch();
}

#include<iostream.h>
#include<conio.h>
#include<string>
void main()
{
string val;
do //executing process.
{
cout<<"Please Enter Password: ";
cin>>val; //user enter value storing in 'val'.
}
while(val != "Khan"); //loop stops when 'val' value Equal to 'Khan'.
cout<<"Password Correct!";
getch();
}

#include<iostream.h>
#include<conio.h>
void main()
{
int a = 0;
do //executing program.
{
int b = 0;
do //executing program
{
cout<<"* ";
b++; //adding 1 to 'b' value.
}
while(b <= a); //loop checking condition.
cout<<endl;
a++; //adding 1 to 'a' value.
}
while(a <= 10); //loop checking condition.
getch();
}