Roman Numerals to Integer using C

 

Roman to Integer Using C program

Program for converting Roman to equivalent Integer:

C Program:

#include<stdio.h> #include<conio.h> int value(char r) { if (r == 'I') return 1; if (r == 'V') return 5; if (r == 'X') return 10; if (r == 'L') return 50; if (r == 'C') return 100; if (r == 'D') return 500; if (r == 'M') return 1000; return -1; } int main() { char s[100]; printf("Enter the Roman:"); gets(s);// gets the input from the user int res=0; int i,j,a,b; for(i=0;i<strlen(s);i++) { a=value(toupper(s[i])); b=value(toupper(s[i+1])); if(a>=b) { res=res+a; } else { res=res+b-a; i++; } } printf("The equivalent integer is %d",res); return 0; }

Output 1:

Output 2:

From the above program,

ü The roman numeral is stored in the array 's'.

ü The romans such as 'I','V','X','L','C','D' has specific decimal values which are listed in the value() function in the above program.

ü Let us take CDCM as the input string.

ü Therefore the length of the string will be 4.

ü Thus the final res value will be 1300 and prints the same.