Is there a way to make an error counter that terminates the program after a specific number of user inputs?

Question

I am a programming beginner. I made a program that converts integer inputs into roman numerals. It's a nonterminating program, and it can only terminate if the user inputs 5 errors.

int main(){
int i;
for(i = 1; i > 0; i++)
{
    int num;
    printf("\n\nEnter a positive integer: ");
    scanf("%d", &num);

    while(num == 0 || num < 0 || num > 3999 || i == 5)
    {
        if(i == 5)
        {
            int ch;
            printf("\n\nYou have reached 5 retries. Do you wish to continue?\n");
            printf("Press 1 to continue.\n");
            printf("Press 2 to terminate the program.\n");
            scanf("%d", &ch);

            if(ch == 1)
            {
                break;
            }
            else if(ch == 2)
            {
                return 0;
            }
            else
            {
                printf("Invalid input. The program will now terminate.");
                return 0;
            }
        }
        else if(num == 0)
        {
           printf("Error: Zero is Nulla");
            break;
        }
        else if(num < 0)
        {
            printf("Error: Input cannot be negative");
            break;
        }
        else if(num > 3999)
        {
            printf("Error: Input cannot be greater than 3999");
            break;
        }
        else
        {
            printf("Error: Input should be a positive integer");
            break;
        }
    }

    while(num > 0 && num <4000)
    {

        if (num >= 1000)       // 1000 - m
        {
           printf("m");
           num -= 1000;
        }
        else if (num >= 900)   // 900 -  cm
        {
           printf("cm");
           num -= 900;
        }
        else if (num >= 500)   // 500 - d
        {
           printf("d");
           num -= 500;
        }
        else if (num >= 400)   // 400 -  cd
        {
           printf("cd");
           num -= 400;
        }
        else if (num >= 100)   // 100 - c
        {
           printf("c");
           num -= 100;
        }
        else if (num >= 90)    // 90 - xc
        {
           printf("xc");
           num -= 90;
        }
        else if (num >= 50)    // 50 - l
        {
           printf("l");
           num -= 50;
        }
        else if (num >= 40)    // 40 - xl
        {
           printf("xl");
           num -= 40;
        }
        else if (num >= 10)    // 10 - x
        {
           printf("x");
           num -= 10;
        }
        else if (num >= 9)     // 9 - ix
        {
           printf("ix");
           num -= 9;
        }
        else if (num >= 5)     // 5 - v
        {
           printf("v");
           num -= 5;
        }
        else if (num >= 4)     // 4 - iv
        {
           printf("iv");
           num -= 4;
        }
        else if (num >= 1)     // 1 - i
        {
           printf("i");
           num -= 1;
        }

    }

}

return 0;}

It stops after 5 user inputs, but I don't want that. I want it to stop after specifically 5 errors. Any help would be appreciated. Thank you

Answer 1

i is incremented in every iteration of the loop, that is why it stops after 5 iterations (5 user inputs). So:

1. Instead of the for loop, you should have a while(1) loop.
2. Instead of int i;, make an int error_counter = 0; before the main loop.
3. Then instead of if(i == 5), you can write ++error_counter; if (error_counter == 5) { ... }.
4. Also, the two inner "while" loop are actually just "if" conditions. So instead of while(num == 0 || num < 0 || num > 3999 || i == 5) and while(num > 0 && num <4000), you should just use if (num <= 0 || num > 3999) {...} else {...}