ropipe/ropipe.c

140 lines
3.0 KiB
C
Raw Normal View History

2021-10-06 17:50:47 +02:00
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define RDIGITS 14
/*
* Returns the value of a roman numeral digit
* @param {char} c - Roman digit
*/
static int roman_to_integer(char c)
{
switch (c)
{
case 'I':
return 1;
case 'V':
return 5;
case 'X':
return 10;
case 'L':
return 50;
case 'C':
return 100;
case 'D':
return 500;
case 'M':
return 1000;
default:
return 0;
}
}
/*
* Returns the interger value of a roman number
* @param {string} s - Roman number
*/
int roman_to_int(char *s)
{
int i, int_num = roman_to_integer(s[0]);
for (i = 1; s[i] != '\0'; i++)
{
int prev_num = roman_to_integer(s[i - 1]);
int cur_num = roman_to_integer(s[i]);
if (prev_num < cur_num)
{
int_num = int_num - prev_num + (cur_num - prev_num);
}
else
{
int_num += cur_num;
}
}
return int_num;
}
/*
* Map of roman digits symbols and their value
* @elem {string} sym - digit symbol
* @elem {int} val - digit symbol
*/
typedef struct
{
char *sym;
int val;
} numeral;
/*
* Returns greatest numeral index
* @elem {numeral} nu - map of roman digits symbols and their value
* @elem {int} num - number
*/
int maxNume(numeral *nu, int num)
{
int i, index;
for (i = 0; i < RDIGITS; i++)
{ //RDIGITS numerals in array
if (nu[i].val <= num)
index = i;
}
//gretest value numeral index, not greater than number
return index;
}
/*
* Prints roman number from integer
* @elem {numeral} nu - map of roman digits symbols and their value
* @elem {int} num - number
*/
void decToRoman(numeral *nu, int num)
{
int max;
if (num != 0)
{
max = maxNume(nu, num);
printf("%s", nu[max].sym);
num -= nu[max].val; //decrease number
decToRoman(nu, num); //recursively print numerals
}
}
/*
* Main
* @elem {int} argc - Argument count
* @elem {string[]} argv - Strings array
*/
int main(int argc, char *argv[])
{
int direction = 0;
/*
* 0: integer to roman (default)
* 1: roman to integer
*/
for (int i = 0; i < argc; i++)
{
if (strcmp(argv[i], "-r"))
{
direction = 1;
}
else
{
direction = 0;
}
}
numeral nume[RDIGITS] = {{"I", 1}, {"IV", 4}, {"V", 5}, {"IX", 9}, {"X", 10}, {"XL", 40}, {"L", 50}, {"XC", 90}, {"C", 100}, {"CD", 400}, {"D", 500}, {"CM", 900}, {"M", 1000}, {"MMMM", 4000}};
char *str1;
int inputint = 0;
switch (direction)
{
case 0:
while (scanf("%s", &str1) && !feof(stdin)) // read integers and convert to roman
{
printf("%d\n", roman_to_int(&str1));
}
break;
case 1:
while (scanf("%d", &inputint) && !feof(stdin)) // read roman and convert to integers
{
decToRoman(nume, inputint);
printf("\n");
}
break;
}
return 0;
}