nbr d'occurences

int occ(char* w, char* f){
    int wlen = strlen(w), flen = strlen(f), i = 0, j, k, res = 0;
    while (i < wlen-flen+1){
        j = 0; k = i;
        while (j < flen && f[j] == w[k]){
            j++; k++;
        }
        if (j == flen)
            res++;
        i++;
    }
    return res;
}