C++ loop coding help - C++ or Other Android Development Languages

I have a program that writes out numbers in roman numerals. I need help writing a loop that repeats the program unless I enter -1 it will stop the program from repeating
Code:
#include <iostream>
using namespace std;
int main()
{
double num;
int intnum, m, d, c, l, x, v, i, n;
cout << "Enter a year (1000-3000) enter -1 to exit: ";
cin >> num;
intnum = (int)num;
m = intnum / 1000;
d = ((intnum%1000) / 500);
c = ((intnum%500) / 100);
l = ((intnum%100) / 50);
x = ((intnum%50) / 10);
v = ((intnum%10) / 5);
i = (intnum%5);
n = m + d + c + l + x + v + i;
while (n > 0)
{
cout << "";
{
for (m; m>0; m--)
cout << "M";
}
{
for (d; d>0; d--)
cout << "D";
}
{
for (c; c>0; c--)
cout << "C";
}
{
for (l; l>0; l--)
cout << "L";
}
{
for (x; x>0; x--)
cout << "X";
}
{
for (v; v>0; v--)
cout << "V";
}
{
for (i; i>0; i--)
cout << "I";
}
n--;
}
return 0;
}

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I think you want to put your code into another loop, like this:
while (1) {
cin >> num;
if (num == -1) break;
// process num here
}

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cycad said:
I think you want to put your code into another loop, like this:
while (1) {
cin >> num;
if (num == -1) break;
// process num here
}
Click to expand...
Click to collapse
It doesn't allow me to quit unless I input -1 which is good BUT it does not repeat the process. After it gives me a roman numeral it just stays there and does nothing until I press -1
I need it to ask me again to enter a year and it will output a roman numeral.

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You need to break this down into functions so it's more readable. If something is confusing keep breaking it down.
Try including <string> and then using this prototype:
string ConvertToRomanNumeral(int n);
Also use this prototype:
int GetInput();
Once you create those functions, then you can do something like this in your main function:
while (1) {
num = GetInput();​if (num == -1) break;​string roman_numerals = ConvertToRomanNumeral(num);​cout << roman_numerals << endl;​}
It's a lot easier to read this way.

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As a side note, you can input values 1 to 3999 for your algorithm to handle them correctly. Twice as much at no extra cost!

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daniel-s said:
As a side note, you can input values up to 3999 for you algorithm to handle them correctly. 33% bonus at no extra cost!
Click to expand...
Click to collapse
Actually this really only works for values up to 3. 4 comes out as IIII which is only right for clocks.

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cycad said:
You need to break this down into functions so it's more readable. If something is confusing keep breaking it down.
Try including <string> and then using this prototype:
string ConvertToRomanNumeral(int n);
Also use this prototype:
int GetInput();
Once you create those functions, then you can do something like this in your main function:
while (1) {
num = GetInput();​if (num == -1) break;​string roman_numerals = ConvertToRomanNumeral(num);​cout << roman_numerals << endl;​}
It's a lot easier to read this way.
Click to expand...
Click to collapse
Thanks got it to work.

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I have another question about another code. When I run it is suppose to give me the answer to the quadratic equation but it doesn't it gives me "No roots available. How can I fix to make it work properly so when I type in 3 numbers it gives me the answer to the quadratic equation and if there is any roots.
Code:
#include <iostream>
#include <cmath>
using namespace std;
double discriminant(double n1, double n2, double n3);
double pos(double n1, double n2, double n3);
double neg(double n1, double n2, double n3);
int main()
{
double a;
double b;
double c;
double discrimi;
double sqr1;
double sqr2;
cout << "Enter the first number in the quadratic equation: ";
cin >> a;
cout << "Enter the second number in the quadratic equation: ";
cin >> b;
cout << "Enter the third number in the quadratic equation: ";
cin >> c;
cout.setf(ios::fixed);
cout.setf(ios::showpoint);
cout.precision(2);
discrimi = discriminant (a,b,c);
if(discrimi > 0 && a != 0) {
sqr1 = pos(a,b,c);
sqr2 = neg(a,b,c);
cout << "In the equation " <<a <<" + "<< b <<" x + "<< c <<" = 0 ";
cout << "Roots of the equation are " << sqr2 <<" & " << sqr2 << endl;
}
else
cout << "No roots availible in the equation. ";
return (0);
}
double discriminant(double a,
double b,
double c){
double discrim;
discrim = pow(b,2) - 4 * a *c;
return(discrim);
}
double pos(double a,
double b,
double c){
double sqr_1;
sqr_1 = (-b + sqrt(pow(b,2) - 4 * a * c)) / (2 * a);
return(sqr_1);
}
double neg(double a,
double b,
double c){
double sqr_2;
sqr_2 = (-b - sqrt(pow(b,2) - 4 * a * c)) / (2 * a);
return(sqr_2);
}

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what is this
If these are parts of an exercise or a homework assignment, then the whole point is for you to debug these issues on your own.
You're asking for some very basic debugging. Let me assure you, it's bad practice to run to the forum the first minute your code breaks. Debugging code that you have authored yourself is something that you must master if you want to become any good. And if you're not interested in becoming good, why are you doing this in the first place?