Need help with C language introductory first year course tha

Need help with C language... introductory first year course, thank you!

Solution

#include <stdio.h>
char romanval[1000];
int i;
//Find out the predigits
void predigit(char num1, char num2)
{
romanval[i++] = num1;
romanval[i++] = num2;
}
//Find out the post digit
void postdigit(char c, int n)
{
int j;
for (j = 0; j < n; j++)
romanval[i++] = c;
}

int main()
{
int j;
long number;
//Loops until -1 is entered as number
do
{
i = 0;
printf(\"\ Enter the number: \");
//Accepts a number
scanf(\"%d\", &number);
//Loops until the entered number is not zero
while (number != 0)
{
//Checks if the number is greater than equal to 1000
if (number >= 1000)
{
//Roman letter is M for 1000
postdigit(\'M\', number / 1000);
number = number - (number / 1000) * 1000;
}
//Checks if the number is greater than equal to 500
else if (number >= 500)
{
if (number < (500 + 4 * 100))
{
//Roman letter is D for 500
postdigit(\'D\', number / 500);
number = number - (number / 500) * 500;
}
else
{
predigit(\'C\',\'M\');
number = number - (1000-100);
}
}
//Checks if the number is greater than equal to 100
else if (number >= 100)
{
if (number < (100 + 3 * 100))
{
//Roman letter is C for 100
postdigit(\'C\', number / 100);
number = number - (number / 100) * 100;
}
else
{
predigit(\'L\', \'D\');
number = number - (500 - 100);
}
}
//Checks if the number is greater than equal to 50
else if (number >= 50 )
{
if (number < (50 + 4 * 10))
{
//Roman letter is L for 50
postdigit(\'L\', number / 50);
number = number - (number / 50) * 50;
}
else
{
predigit(\'X\',\'C\');
number = number - (100-10);
}
}
//Checks if the number is greater than equal to 10
else if (number >= 10)
{
if (number < (10 + 3 * 10))
{
//Roman letter is X for 10
postdigit(\'X\', number / 10);
number = number - (number / 10) * 10;
}
else
{
predigit(\'X\',\'L\');
number = number - (50 - 10);
}
}
//Checks if the number is greater than equal to 5
else if (number >= 5)
{
if (number < (5 + 4 * 1))
{
//Roman letter is V for 5
postdigit(\'V\', number / 5);
number = number - (number / 5) * 5;
}
else
{
predigit(\'I\', \'X\');
number = number - (10 - 1);
}
}
//Checks if the number is greater than equal to 1
else if (number >= 1)
{
if (number < 4)
{
//Roman letter is I for 1
postdigit(\'I\', number / 1);
number = number - (number / 1) * 1;
}
else
{
predigit(\'I\', \'V\');
number = number - (5 - 1);
}
}
}
//Displays the roman letter format for inputted number
printf(\"Roman number is: \");
for(j = 0; j < i; j++)
printf(\"%c\", romanval[j]);

}while(number != -1);
return 0;
}

Output:

Enter the number: 33
Roman number is: XXXIII
Enter the number: 61
Roman number is: LXI
Enter the number: 123
Roman number is: CXXIII
Enter the number: 789
Roman number is: DCCLXXXIX
Enter the number: 652
Roman number is: DCLII
Enter the number: 1234
Roman number is: MCCXXXIV
Enter the number: 658
Roman number is: DCLVIII
Enter the number: -1