OR-Skripta Adijata-zad 3-Broj Zamijeni Zbirom Cifara

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

void Unos (char *s) {
    int i=0;
    char c;
    do {
            c=getchar();
            s[i]=c;
            i++;
    }   while (c!='\n' && i<100);
    s[i-1]='\0';
}

int length(char *s) {
    int duz=0,i=0;
    while (s[i++]!='\0') duz++;
    return duz;
}
int JeLiBroj (char c)
{
    if (c>='0' && c<='9') return 1;
    return 0;
}

void cut(char *string, int indeks, int len)
{
    int i,duz=length(string);

    for(i = indeks; i <= duz - len; i++)
    {
        string[i] = string[i + len];
    }

}

int obrni (int n) {
    int nb=0, k=1;
    while (n!=0) {
        nb=nb*10+n%10;
        n/=10;
    }
    return nb;
}

void BrojUString (char *s, int n) {
    int duzina=length(s), i=0, nb;
    nb=obrni(n);
    while (nb!=0) {
            s[i]=nb%10+'0';
            i++;
            nb/=10;
    }
    s[i]='\0';
}




void insert (char *s1, char *s2, int indeks) {
    int i;
    for (i=length(s1)+length(s2); i>=indeks+length(s2); i--)
           s1[i]=s1[i-length(s2)];

    for (i=0; i<length(s2); i++) {
            s1[i+indeks]=s2[i];
    }
}

void Zamijeni ( char *s) {
    int suma=0, i,j=0, duzina=length(s), poc, kraj;
    char broj[20];
    for (i=0; i<duzina; i++) {
            if (JeLiBroj(s[i])) {
                    poc=i;
                     suma+=s[i]-'0';
                     i++;
               while (JeLiBroj(s[i])) {
                     suma+=s[i]-'0';
                     i++;
               }
               BrojUString(broj,suma);
               kraj=i;
            cut(s,poc,kraj-poc);
            i-=(kraj-poc);
            insert(s,broj,poc);
            i+=length(broj);

            }
             suma=0;
    }
}


int main () {
    char s[100];
     Unos(s);
    Zamijeni(s);
    printf("%s", s);
    return 0;

}