C homework - string loops replacements -

i know it's little unorthodox , cost me downvotes, since it's due in 1 hour , have no idea begin thought i'd ask guys.

basically i'm presented string contains placeholders in + form, example:

1+2+5 

i have create function print out possibilities of placing different combinations of given series of digits. i.e. series:

[9,8,6] // string array 

the output be

16265 16285 16295 18265 18285 18295 19265 19285 19295 

so each input (number of digits)^(number of placeholders) lines of output. digits 0-9 , maximum form of digits string [0,1,2,3,4,5,6,7,8,9]. original string can have many placeholders (as you'd expect output can lengthly).

i have in c, preferably no recursion. again appreciate help, couldn't more thankful right now.

if can offer idea, simplified way @ solving this, in different language or recursively, it'd still ok, use general concept , move on there.

it prints them in different order, not matter. , it's not recursive.

#include <stdlib.h> #include <stdio.h>  int // 0 if no more. get_string(char* s, const char* spare_chr, int spare_cnt, int comb_num){     (; *s; s++){         if (*s != '+') continue;         *s = spare_chr[comb_num % spare_cnt];         comb_num /= spare_cnt;     };     return !comb_num; };  int main(){     const char* spare_str = "986";     int num = 0;     while (1){         char str[] = "1+2+5";         if (!get_string(str, spare_str, strlen(spare_str), num++))              break; // done         printf("str num %2d: %s\n", num, str);     };     return 0; };