Question

I'm trying to write in C++ a way to have the user input an double one at a time and have the program output (on entering 0) the number of times those variables differ by at least 1. For example if I enter 1, 1.7, 0.8, -0.1, -1, 0 ... I should get back 4. (or if I just input 0, the output should just be 0). I'm having trouble understanding how to use a while/for operation to make this happen. This is what I have so far.

#include <iostream>
using namespace std;

int main ()
{
    double n1, n2;
    int n = 0;
  
    cout << "Enter two seperate numbers." << endl;
    cin >> n1 >> n2;
  
    while (n1 || n2 != 0) {
        if (((n2 - n1) > -1) && ((n2 - n1) < 1)) {
            n++;
            n1 = n2;
       }
        else {
            cout << n <<endl;
        }
        cout << "Enter another number or enter 0 to quit." << endl;
        cin >> n1 >> endl;
    }
        return 0;
}

Where have I gone wrong? Am I way off base?

Answer 1

Hi,

From the above problem what I understand is the program is not terminating when the user enters 0 for n1.

It won't stop with the given conditions because, in while loop what you are checking is the while loop should continue when n1 or n2 is not 0. so if n2 has non zero the loop always runs even the n1 is 0. Because the OR condition will give true if any of them are true.

In your case if n2 is non zero and n1 is zero, here while(n!=0 || n2!=0) you used. the n2!=0 condition will always runs.

I have solved and added a bit of code. If you don't need of that case you can remove that part from the program.

I'll make bold what I've changed/modified. in your code.

MyProgram.cpp

#include <iostream>
using namespace std;

int main ()
{
double n1, n2;
int n = 0;
  
cout << "Enter two seperate numbers." << endl;
cin >> n1 >> n2;
if(n2!=0 && n1!=0){//enter to loop if the n1 and n2 are not zeros.
while (n1!=0) {//we reading only n1 so we wrote n1 only
if (((n2 - n1) > -1) && ((n2 - n1) < 1)) {
n++;
n1 = n2;
}
else {
cout << n <<endl;
}
cout << "Enter another number or enter 0 to quit." << endl;
cin >> n1;
}
}else{
cout<<"n2 or n1 is 0";//just a output
}
return 0;
}

I have given the code.

I think there is no need for the output screenshot. If you get any doubt please comment under this answer. I'll clarify your doubt asap.

Thumbs Up!!!

Thank you!!