Dynamic allocation of multi dimensional array

[Mohan Giri]

Hi everyone,
could you tell me how to assign values to dynamically created multi dimensional array???

I tried this code. I am getting error : Invalid direction



#include<stdio.h>
#include<conio.h>
main()
{
int *a;
int i,j,k;
int l,m,n;
//clrscr();
printf("Enter i,j,k value to create multidimensional array:");
scanf("%d %d %d",&i,&j,&k);
printf("I=%d J=%d K=%d",i,j,k);
a=(int *)malloc(i*j*k*sizeof(int));
for(l=0;l<i;l++)
{
for(m=0;m<j;m++)
{
for(n=0;n<k;n++)
{
printf("Enter array elements:");
a[n][m][k])=getche();
}
}
}
for(l=0;l<i;l++)
{
printf("\n");
for(m=0;m<j;m++)
{
for(n=0;n<k;n++)
{
printf("%d",a[n,m,k]); /* Error at this line: Invalid indirection */

}
}
}

getch();


}


Anyone can help me to assign values???

 

[M4A1]

I would read it but it's not properly formatted and I'm not going to sit here and decipher it. Also, all of your questions seem like homework questions. I may be wrong, however if they are, the approach you're taking is wrong

 

[Mohan Giri]

I dont know what is wrong with me. I dont know how to do here. I tried a quite enough. So I am just asking you friends to help me. Not to write entire code. Just asking what can I do there. Thats it. More over I am novice in programming. I am trying to make me expert. Is there anything wrong in my attitude. Ya. I accept my logical thinking level is low. So I am trying to improvise it. If you have any idea guide me. Thank u. Bye


After this I tried this code: But this is also not working properly. Can u tell me what is wrong in my concept???

#include<stdio.h>
/*#include<alloc.h>*/
#include<conio.h>
main()
{
int *a;
int i,j,k;
int l,m,n;


clrscr();

printf("Enter i,j,k value to create multidimensional array:");
scanf("%d %d %d",&i,&j,&k);

printf("I=%d J=%d K=%d\n",i,j,k);

a=(int *)malloc(i*j*k*sizeof(int));
/* printf("%u",a[i,j,k]); *
a++;
printf("%u",a); */
if(a==NULL)
printf("Error:array not initialised\n");
else
{
for(l=0;l<i;l++)
{
printf("\n");
for(m=0;m<j;m++)
{
for(n=0;n<k;n++)
{
printf("Enter Elements:");
scanf("%d",&a[l,m,n]);

}

}
} }
for(l=0;l<i;l++)
{
printf("\n");
for(m=0;m<j;m++)
{
printf("\n");
for(n=0;n<k;n++)
{
printf("%d ",a[l,m,n]);

}
}
}

getch();


}

More over while I am writing my query I am indenting my code properly. But when I post it it becomes like this.

 

[Alex81388]

What line of code does the error point to?

 

[Mohan Giri]

I am getting error at scanf function at first for loop set. ie while assigning values to the array

 

[Mohan Giri]

Some how I got a answer. But its not correct. While I am print the values at where I receive the values its printing correctly. But in final result the result is not correct. Anyone can pointout what I did wrong??

Here is my code::

#include<stdio.h>
#include<conio.h>
main()
{
int *a;
int i,j,k;
int l,m,n;


clrscr();

printf("Enter i,j,k value to create multidimensional array:");
scanf("%d %d %d",&i,&j,&k);

printf("I=%d J=%d K=%d\n",i,j,k);

a=(int *)malloc(i*j*k*sizeof(int));

if(a==NULL)
printf("Error:array not initialised\n");
else
{
for(l=0;l<i;l++)
{
printf("\n");
for(m=0;m<j;m++)
{
for(n=0;n<k;n++)
{
printf("Enter Elements:");
scanf("%d",(((a+l)+m)+n));
printf("a[%d][%d][%d]=%d",l,m,n,*(((a+l)+m)+n));

}

}
} }
for(l=0;l<i;l++)
{
printf("\n");
for(m=0;m<j;m++)
{
printf("\n");
for(n=0;n<k;n++)
{
printf("a[%d][%d][%d]=%2d ",l,m,n,*(((a+l)+m)+n));

}
}
}

getch();


}

 

[C.Ingram]

If

l = 1
m = 2
n = 1

You would be using the

 1 + 2 + 1 = 4

4th int in the memory you allocated.

If

l = 2
m = 1
n = 1

You would be using the

 2 + 1 + 1 = 4

4th int in the memory you allocated.

This is a problem.

If you know the size of each dimension, you can seperate out blocks logically. If you havea 2x2x2 array, you need 8 bytes to store the entire array. The first dimension is 2x2=4 bytes. The second dimension is 2 bytes. The third dimension is one byte each. Knowing this, you can calculate a uniuqe position in the memory for each index.

 

[Mohan Giri]

OK Mr.C.Ingram. Thank you for pointing out my error. I will try to solve this.

 

[furtivefelon]

ok.. next time use [CODE ] [ /CODE] to post your code, minus the spaces within the bracket

 

[M4A1]

If that's too complicating to follow, you can always use www.rafb.net/paste