Roman To Integer

#include <stdio.h>
#include <string.h>


int value(char r) {
    switch (r) {
        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 -1;
    }
}

int romanToInt(char roman[]) {
    int total = 0;
    int i;
    for (i = 0; i < strlen(roman); i++) {
        int s1 = value(roman[i]);

        if (i + 1 < strlen(roman)) {
            int s2 = value(roman[i + 1]);
            if (s1 >= s2) {
                total += s1;
            } else {
                total += (s2 - s1);
                i++; 
            }
        } else {
            total += s1;
        }
    }
    return total;
}

int main() {
    char roman[20];

    printf("Enter a Roman numeral (in uppercase): ");
    scanf("%s", roman);

    printf("Integer value: %d\n", romanToInt(roman));

    return 0;
}