Scanf() sauté

#include <stdio.h>
 #include <stdlib.h>
 
 int r_to_a(char roman[], int arabe[], char c)
 {
     for (int i = 0; i < 7; i++)
     {   
         if (c == roman[i])
         {
             return arabe[i];
         }
     }   
 
     return -1; 
 }

int convert(char tab[], char roman[], int arabe[], int size)
 {
     int result = 0;
     for (int i = 0; i < size; i++)
     {   
         if (i > 0 && r_to_a(roman, arabe, tab[i]) < r_to_a(roman, arabe, tab[i + 1]))
         {
             result += r_to_a(roman, arabe, tab[i + 1]) - r_to_a(roman, arabe, tab[i]);
             i++;
             printf("RESULT : %d\n", result);
         }
         else if (i > 0 && r_to_a(roman, arabe, tab[i]) >= r_to_a(roman, arabe, tab[i - 1]))
         {
             result += r_to_a(roman, arabe, tab[i]);
             printf("RESULT : %d\n", result);
         }
         else
         {
             result += r_to_a(roman, arabe, tab[i]);
             printf("RESULT : %d\n", result);
         }
     }
     return result;
 }

int main()
 {
     char roman[7] = {'I','V','X','L','C','D','M'};
     int  arabe[7] = { 1, 5, 10, 50, 100, 500, 1000};
     
    char test[] = "MCMLXXXV";
    int result = convert(test, roman, arabe, 8);
    printf("RESULT RECEIVED : %d\n", result);    
    printf("RESULT EXPECTED : 1985");      
    return 0;  
}