Release vs Debug: Bad Memory Access

Question

Hello everyone.
For a school assignment I have to write a program that sorts bottles (inputed by the user) into three bins, and state the minimum amount of moves it takes. I've completed the program, that's not really the problem.
There is a drop down menu up on the top left, and it gives me the option between 'Release' and 'Debug' (under Active Configuration). Now I don't quite understand the difference, but expected for the final copy it should be compiles with it set to Release. But that's just an assumption.
The problem is, or maybe this is just a question, when I set it to Debug and build my program, it runs great. If I change this option to Release and run the program I get "EXCBADACCESS" and the program fails.
My main worry is this might indicate a potential problem with compatibility on other platforms (maybe). I've compiled the program in Terminal with GCC and it works fine there as well. I will post my code below if it helps any. My hope is this is either a bug in xcode, or simply nothing to worry about.
I've underlined the area XCode highlights when the error occurs. Thank you.
#include <stdio.h>
#include <stdlib.h>
const char bottle_colour[][6]={"red","white","blue"};
int main()
int i,low,move[6],bottles[3][3];// bottles[bin][colour]
for (i=0;i<3;i++)
printf("Please enter the amount of %s bottles in each bin with a space inbetween each amount\n",bottle_colour);
scanf("%i%i%i",&bottles[0],&bottles[1],&bottles[2]);
printf("\n");
move[3] += bottles[1][0] + bottles[2][0];// Moving all red bottles to bin 1
move[3] += bottles[0][1] + bottles[2][1];// Moving all white bottles to bin 2
move[3] += bottles[0][2] + bottles[1][2];// Moving all blue bottles to bin 3
move[2] += bottles[1][0] + bottles[2][0];// Moving all red bottles to bin 1
move[2] += bottles[0][1] + bottles[1][1];// Moving all white bottles to bin 3
move[2] += bottles[0][2] + bottles[2][2];// Moving all blue bottles to bin 2
move[5] += bottles[0][0] + bottles[2][0];// Moving all red bottles to bin 2
move[5] += bottles[1][1] + bottles[2][1];// Moving all white bottles to bin 1
move[5] += bottles[0][2] + bottles[1][2];// Moving all blue bottles to bin 3
move[4] += bottles[0][0] + bottles[2][0];// Moving all red bottles to bin 2
move[4] += bottles[0][1] + bottles[1][1];// Moving all white bottles to bin 3
move[4] += bottles[1][2] + bottles[2][2];// Moving all blue bottles to bin 1
move[1] += bottles[0][0] + bottles[1][0];// Moving all red bottles to bin 3
move[1] += bottles[1][1] + bottles[2][1];// Moving all white bottles to bin 1
move[1] += bottles[0][2] + bottles[2][2];// Moving all blue bottles to bin 2
move[0] += bottles[0][0] + bottles[1][0];// Moving all red bottles to bin 3
move[0] += bottles[0][1] + bottles[2][1];// Moving all white bottles to bin 2
move[0] += bottles[1][2] + bottles[2][2];// Moving all blue bottles to bin 1
for (i=0;i<5;i++)
_if (move[i+1] < move && move[i+1] < move[low])_
low = i + 1;
printf("\nThe lowest amount of moves it would take is %i.",move[low]);

Answer 1

Well, welcome to programming.
The code as printed obviously isn't quite right due to formatting problems. There's a way to format it so it is displayed correctly but I don't know it off hand.
If you use look at the build warnings you'll get a pretty good idea what is going on. In general there should be few or zero warnings in the build process. They're there for a reason. C provides a lot of rope.
A few issues right away from the command line compiler:
s.c:12: warning: format ‘%s’ expects type ‘char *’, but argument 2 has type ‘const char (*)[6]’
s.c:13: warning: format ‘%i’ expects type ‘int *’, but argument 2 has type ‘int (*)[3]’
s.c:13: warning: format ‘%i’ expects type ‘int *’, but argument 3 has type ‘int (*)[3]’
s.c:13: warning: format ‘%i’ expects type ‘int *’, but argument 4 has type ‘int (*)[3]’
I presume the following code
if (movei+1 < move && movei+1 < movelow)
low = i + 1;
is
if (move[i+1] < move && move[i+1] < move[low])
low = i + 1;
If so, I see the following warning:
s.c:43: warning: comparison between pointer and integer
Trust me, the issue is not portability at all nor a bug in Xcode. There are significant bugs in this code that just happen to compile.
For instance, in line 12, the %s takes a pointer to a string yet a pointer to an array of strings has been provided.
In line 13, the scanf %i operator requires a pointer to an integer yet a pointer to an array of pointers as been provided. You should have passed something such as &bottles[x][y] for each of those arguments.
If you actually have 'move && move[i+1]' in the code, the code is comparing an address to an integer and I'm sure that's not intended.
Lastly, 'low' is not initialized (those are difficult to find and the compiler does not warn of them even when using the -Wall flag). Probably should be set to zero. Different compilers and platforms vary on guarantees of a zero value.
Since this is a project in school I will stop at this (and there are more issues in the code than I have stated).
It'll all come in time. Good luck to you.