Accept Number Infinitely

Accept Number till negative number is not entered

#include<iostream.h>
#include<conio.h>

void main()
{
    int n;
    clrscr();

    do
    {
        cout<<"Enter number: ";
        cin>>n;
    }
    while( n >= 0);
}



Accept Number till user say 'No'

#include<iostream.h>
#include<conio.h>

void main()
{
    int n;
    char ch = 'Y', ans, k = 'y';
    clrscr();

    do
    {
        cout<<"Enter number: ";
        cin>>n;
        cout<<"Do you want to continue";
        cout<<"\nThe answer is: ";
        cin>>ans;
    }
    while( ans == ch || k == ans);
}



Accept addition of Numbers till sum is even

#include<iostream.h>
#include<conio.h>

void main()
{
    int a, b, sum;
    clrscr();

    do
    {
        cout<<"Enter number: ";
        cin>>a>>b;

        sum = a + b;
        cout<<"Sum is: "<<sum;
    }
    while( sum % 2 == 0);
}



Accept Number till negative number is not entered & print sum of all positive numbers

#include<iostream.h>
#include<conio.h>

void main()
{
    int no, sum = 0;
    clrscr();

    do
    {
        cout<<"Enter number: ";
        cin>>no;

        if( no >= 0)
            sum = sum + no;
    }
    while( no >= 0);

    cout<<"Sum of all positive numbers is: "<<sum;
}