C++ - Check if there are no even numbers in given interval - c++

Question

I have to write a program on C++ which finds all even numbers in range given by user. Here's the code I have written so far:
#pragma hdrstop
#pragma argsused
#include <tchar.h>
#include <iostream.h>
#include <conio.h>
#include <stdio.h>
#include <math.h>
void main() {
int m, n, j = 1; // m and n- numbers entered by user, j- product of all even numbers in interval
char atbilde; // A letter entered by user, of which system decides wether to continue or to stop programme
do {
j = 1;
cout << "Enter the min number of interval! ";
cin >> n;
cout << "Enter the max number of interval! ";
cin >> m;
if (n > m) { // Detects wether „n” is larger than „m”
cout << "Max number of interval has to be larger than min number!";
do { // If max number is larger than min number, screen is cleared
cin.clear();
cin.ignore();
cout << "Enter the numbers again!";
cout << "\n Enter the min number of interval! ";
cin >> n;
cout << "\n Enter the max number of interval! ";
cin >> m;
}
while (n > m);
}
cout << "Even numbers in given interval: ";
for (; n <= m; n++)
{
if (n % 2 == 0)
{ // Detects, wether there are even numbers in given interval
if (n != 0) {
cout << n << " ";
j *= n;
}
if ((n == m) && (n % 2 != 0)) {
j=0;
}
}
}
cout << "\n The product of found even numbers: " << j << " ";
cout << "\n Repeat? (Y/N) ";
cin >> answer;
system("cls");
}
while (tolower(answer) != 'n');
}
But I have a small problem, so I can't get the program 100% done because of the problem.
Like, user enters range, whose min and max number is the same and it's odd. In that case program has to print out a sentence "there were no even numbers in interval" in place of "The product of found even numbers:". I have searched the solution in internet, but haven't found it.
I hope you'll know the right solution.

Answer 1

Some hints to help you along the way: If there was no even number in the range, you will not enter into the loop. What will j be then? How do you react on that value?

Answer 2

I tried to fix your code, I did the best I could from what I understood you were tring to do.
I cleaned it up, fixed spelling and grammer, I deleted unnecessary stuff, I also made it more compact and nice to look at.
#include <iostream>
int main() {
int max=0, min=1, sum=0; product = 1, amount = 0; // max, min - entered by user, product - product of all even numbers in interval, sum - sum of all even numbers in interval. amount - amount of even numbers in interval
char x=Y; // Entered by user to know if to quit or continue to continue.
while ((x == Y) || (x == y))
{
while (min > max) { // System detects whether minimum is bigger than maximum
cin.clear(); // Clears screen so if this part runs again it wouldn't get messy.
cin.ignore();
cout << "Max has to be larger than min!";
cout << "\n Enter the min number of interval! ";
cin >> min;
cout << "\n Enter the max number of interval! ";
cin >> max;
}
for (; min <= max; min++)
{
if (min % 2 == 0)
{
sum+=n;
count++;
product*=n;
}
}
if (count == 0)
{
product=0;
cout << "There are no even numbers in interval!";
}
else
{
cout << "\n The amount of the even numbers in interval: " << amount << ",the product of the even numbers: " << product << ",the sum of the even numbers: " sum << "\n\n";
}
cout << "Repeat? (Y/N) ";
x=getchar;
system("cls");
}
return 0;
}