OR-Broj Duplih Slova

#include <stdio.h>
#include <stdlib.h>


int length (char *s) {
    int d=0;
    while (*(s++)!='\0') d++;
    return d;
}
int JeLiMalo (char c) {
    if (c>='a' && c<='z') return 1;
    return 0;
}
int JeLiVeliko (char c) {
    if (c>='A' && c<='Z') return 1;
    return 0;
}

int BrojDuplihSlova(char *s) {
    int slova[27], brojac=0, duzina=length(s), i;
    for(i=0; i<27; i++) slova[i]=0;

    for (i=0; i<duzina; i++) {
            if (JeLiMalo(s[i])) slova[s[i]-'a']++;
            else if (JeLiVeliko(s[i])) slova[s[i]-'A']++;
    }
    for (i=0; i<27; i++) {
            if (slova[i]==2) brojac++;
    }
    return brojac;
}

int main () {
    char s[]="Selma je bila ovdje.";
    printf("Broj duplih slova: %d", BrojDuplihSlova(s));
    return 0;
}