char / int system, C

C kode 

 //
 //  main.c
 //  SekundOmregner
 //
 
 #include <stdio.h>
 
 //Prototype
 void user_instr(void);
 void convert_seconds(int seconds, char *hours, char *mins, char *secs);
 char need_zeros(int input);
 
 int main ()
 {
     
     int seconds;
     char hours[128], mins[8], secs[8];
     
     user_instr();
     
     printf("\n\nPlease enter the ammount of seconds you wish to convert: ");
     scanf("%d", &seconds);
     
     convert_seconds(seconds, &hours, &mins, &secs);
     
     printf("%d seconds is equal to: ", seconds);    
     printf("\n\n%s Hours\n%s Minutes\n%s Seconds", hours, mins, secs);
     printf("\n\n%s:%s:%s", hours, mins, secs);
     
     return 0;
 }
 
 void user_instr(void){
     
     printf("Welcome to the Seconds converter program\n");
     printf("Enter any given ammount of seconds to convert it\n");
     printf("into hours, minutes and seconds");
     
 }
 
 void convert_seconds(int seconds, char *hours, char *mins, char *secs){
     
     int temp_hour, temp_min, temp_sec;
     
     //Convert seconds to hours (first minutes, then hours)
     temp_hour = seconds/60/60;
     temp_hour = 5;
     
     *hours = need_zeros(temp_hour);
     
     //Minutes left from hours
     temp_min = seconds/60 - *hours*60;
     temp_min = 5;
     *mins = need_zeros(temp_min);
     
     
     //Seconds left from minutes
     temp_sec = seconds - ((*hours * 60 * 60) + (*mins * 60));
     temp_sec = 5;
     *secs = need_zeros(temp_sec);
     
 }
 
 char need_zeros(int input){
     
     char temp[20];
     
     if(input < 10){
     
         sprintf(temp, "%02d", input);
     
     }
     
     return temp;
 
 }