HW Help - Struct and Strings

[Darklegion]

Hi,

I'm banging my head over this homework assignment after spending nearly 5 hours on it myself. I'm giving in and asking for help.

Here is the code I have so far and once I get past this part I will be able to complete the rest of the assignment easily.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "myHeader.h"

int main() {
	
	struct taskList *schedule;
	
	printf("Enter a task name, unit time, and prerequisite. If no prerequisite, enter none:\n");
	scanf("%c %d %c", &schedule->task, &schedule->time, &schedule->preReq);
	printf("\n\n\nTask: %c \nTime: %d \nPreRequisite: %c\n", schedule->task, schedule->time, schedule->preReq);

	return 0;
}

struct taskList {
	char task;
	int time;
	char preReq;
};

Example input:
Bake 30 Mix

Bake - Task that needs to be completed
30 - Time it takes to complete
Mix - Prerequisite task, must be completed first

Issue I have:
I am unable to get the strings Bake and Mix stored into their respective variables and with the code I have posted above I get this error: Segmentation Fault in Unix.

I've been told to use malloc() but I never used it before and not sure how to go about implementing it if I do in fact need to use it.

This assignment must be in C even though I prefer C++.

Thank you for your help.

[MK27]

I've been told to use malloc() but I never used it before and not sure how to go about implementing it if I do in fact need to use it.

malloc is a pretty fundamental command. You should look it up somewhere...anyway, right now you are using a pointer:

	struct taskList *schedule;

If you remove the asterisk, you won't have to malloc any memory because "schedule" will be an actual instance of "taskList". In that case, you will need to change your notation from indirect to direct:

schedule->task  //indirect
schedule.task   //direct

Alternatively, here's how you would malloc the pointer:

	struct taskList *schedule = malloc(sizeof(struct taskList));

You then need to free the memory at the end of the program:

        free(schedule);

This assignment must be in C even though I prefer C++.

Hmmm. The fact that you do not understand pointers and apparently spent hours struggling with this is nothing to be ashamed of, but it is evidence that you cannot code in either C or C++ (no offense!). So I am kind of curious why you would feel this way? I'm just raising the issue because it seems silly to be starting out with a (unjustifiable) negative attitude, esp if it is because of something even more silly said by someone else...in any case good luck, cboard is a great place to look for help.

[mouse666666]

you are scanning for a string not a character therefor you should use %s not %c.
You should decleare an array for your string. to set aside memory or maybe you can just post your assigment and ill try to do it.

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


struct taskList {
	char task[100];
	int time;
	char preReq[100];
};


int main() {
	
	struct taskList schedule;
    int i;	
	printf("Enter a task name, unit time, and prerequisite. If no prerequisite, enter none:\n");
	scanf("%s %d %s", schedule.task, &schedule.time, schedule.preReq);
	printf("\n\n\nTask: %s \nTime: %d \nPreRequisite: %s\n", schedule.task, schedule.time, schedule.preReq);

    getch();
	return 0;
}

[Soulzityr]

to malloc, you should do

schedule= malloc (sizeof(struct taskList));

also, your struct should have an array of chars (this makes strings) instead of just a single char, which would be one instead of many. Your code looks like this:

struct taskList {
	char task;
	int time;
	char preReq;
};

It should look like

struct taskList {
	char task[30]; //30 is just a random number; it should be whatever you want or what
                               //your assignment requires
	int time;
	char preReq[30]; //same as above
};

With that change, you should change from

"%c" to %s"

for example

scanf("%s %d %s", schedule->task, &schedule->time, schedule->preReq);

but like someone said, you dont HAVE to make a pointer and malloc it. You can just make a direct structure and then access its variables like this

schedule.task, schedule.time,...

[Darklegion]

Thank you for the help so far, I will take a look over it and see how to implement it.

As for my comment about wanting to program in C++ rather than C:

I've been programming in C++ for 2 years now and understand the syntax inside and out. For some reason the syntax of C throws me off on everything.

This is my third assignment in programming with C so my time spent using C has been very minimal.

Edit: I would also like to add that I have done an assignment similar to this in the past but it was in C++ and I am having trouble converting that assignment into this C assignment.