I'm trying to add classes which duration is in minutes into a weekly schedule held on work days from 8:00 to 21:00. The classes should be added to the first free term.
My algorithm is the following:
- I convert every class term into minutes and compare it to 1260 (because 21 hours are equal to 1260 minutes)
- if the number is less or equal to 1260 it should be added to the end of last term
- if the number is grater than 1260 it should be added on a new work day starting from 8:00
Code:
#include <stdio.h>
#include <string.h>
struct Time {
int hour, minute;
} start, end;
struct Class {
char subject[100];
struct Time start, end;
} schedule[100];
int add = 0;
void add_class(struct Class schedule[], int number_of_classes, char *subject,
int duration) {
int time_in_minutes;
add = duration;
schedule[0].start.hour = 8;
schedule[0].start.minute = 0;
if (number_of_classes == 0) {
time_in_minutes =
(schedule->start.hour) * 60 schedule->start.minute duration;
schedule->end.hour = (int)(time_in_minutes / 60);
schedule->end.minute = time_in_minutes - (schedule->end.hour) * 60;
strcpy(schedule[number_of_classes].subject, subject);
} else {
int previous = number_of_classes - 1;
int temp_hour = schedule[previous].end.hour;
int temp_minute = schedule[previous].end.minute;
time_in_minutes = temp_hour * 60 temp_minute duration;
if (time_in_minutes <= 1260) {
strcpy(schedule[number_of_classes].subject, subject);
schedule[number_of_classes].start.hour = temp_hour;
schedule[number_of_classes].start.minute = temp_minute;
schedule[number_of_classes].end.hour = (int)(time_in_minutes / 60);
schedule[number_of_classes].end.minute =
time_in_minutes - (schedule[number_of_classes].end.hour) * 60;
}
if (time_in_minutes > 1260) {
time_in_minutes = 8 * 60 duration;
schedule[number_of_classes].start.hour = 8;
schedule[number_of_classes].start.minute = 0;
schedule[number_of_classes].end.hour = (int)(time_in_minutes / 60);
schedule[number_of_classes].end.minute =
time_in_minutes - (schedule[number_of_classes].end.hour) * 60;
strcpy(schedule[number_of_classes].subject, subject);
}
}
}
void print_day(int day) {
switch (day) {
case 0:
printf("MONDAY:\n");
break;
case 1:
printf("TUESDAY:\n");
break;
case 2:
printf("WEDNESDAY:\n");
break;
case 3:
printf("THURSDAY:\n");
break;
case 4:
printf("FRIDAY:\n");
break;
default:
printf("WRONG\n");
}
}
void print_schedule(struct Class schedule[], int number_of_classes) {
int i;
int day_printed = 0;
int day = 0;
for (i = 0; i < number_of_classes; i ) {
if (day_printed == 0)
print_day(day);
if (schedule[i].start.hour > 9)
printf("%d:", schedule[i].start.hour);
else
printf("0%d:", schedule[i].start.hour);
if (schedule[i].start.minute > 9)
printf("%d - ", schedule[i].start.minute);
else
printf("0%d - ", schedule[i].start.minute);
if (schedule[i].end.hour > 9)
printf("%d:", schedule[i].end.hour);
else
printf("0%d:", schedule[i].end.hour);
if (schedule[i].end.minute > 9)
printf("%d ", schedule[i].end.minute);
else
printf("0%d ", schedule[i].end.minute);
int time_in_minutes =
(schedule[i].end.hour) * 60 schedule[i].end.minute add;
printf("%s\n", schedule[i].subject);
day_printed ;
if (time_in_minutes > 1260) {
day ;
day_printed = 0;
}
}
}
void main() {
int duration_arr[10] = {100, 200, 100, 300, 500, 600, 200, 100, 400, 300}, i;
char subject_arr[10][15] = {
"Subject 1", "Subject 2", "Subject 3", "Subject 4", "Subject 5",
"Subject 6", "Subject 7", "Subject 8", "Subject 9", "Subject 10"};
for (i = 0; i < 10; i )
add_class(schedule, i, subject_arr[i], duration_arr[i]);
print_schedule(schedule, 10);
}
My output:
MONDAY:
08:00 - 09:40 Subject 1
09:40 - 13:00 Subject 2
13:00 - 14:40 Subject 3
14:40 - 19:40 Subject 4
TUESDAY:
08:00 - 16:20 Subject 5
WEDNESDAY:
08:00 - 18:00 Subject 6
THURSDAY:
08:00 - 11:20 Subject 7
11:20 - 13:00 Subject 8
13:00 - 19:40 Subject 9
FRIDAY:
08:00 - 13:00 Subject 10
The correct output would be with Subject 7 on Tuesday (because of that Subject 10 would move to Thursday) like this.
My idea is:
- start with index of zero and and check if class term was added to schedule
- if it was added continue
- add it to schedule right after last if it's less or equal to 1260
- add it to start of next day (8:00) if it's grater than 1260
Could you help me modify my code for this idea or give me some better approach?
CodePudding user response：
The code of yours works properly, however the idea has one flaw: it fits a new class to the first available time-slot after the previously added class, but it does not try to fit the class to the first available time-slot in the whole week. Note that in add_class function, there is no behaviour to check if Subject 7 can fit on Tuesday, it is only compared to Wednesday, where Subject 6 was placed.
This is because you are storing the classes in a static array of structures, which can be suboptimal for this problem. I think you would be better off using linked lists. You could create a linked lists of the scheduled classes (containing also the day of the week) and in add_class function you could check the same you are checking (minutes in the day), but "day-by-day". Then you could add a new class in the correct position (in your case, Subject 7 would go after Subject 5).
CodePudding user response：
I tried to compare struct array after adding all classes with this:
void swap(int a[], int b, int c) {
int temp = a[b];
a[b] = a[c];
a[b] = temp;
}
void sort(struct Class schedule[], int n) {
int i,sum=0;
for (i = 0; i < n; i ) {
int time_in_minutes = (schedule[i].start.hour) * 60 schedule[i].start.minute;
schedule[i].end.hour = (int)(time_in_minutes / 60);
schedule[i].end.minute = time_in_minutes - (schedule[i].end.hour) * 60;
sum =time_in_minutes;
if (sum > 1260) {
swap(schedule,i,i )
}
}
}
Why this doesn't work? Could you help me to sort it correctly?