PALIN_runtime error (SIGSEGV)

[pandia]

Every time I run my program, I get this error. Pls help me:(

#include
int palindrome(int);

void main()
{
int *a,c,t,i;
scanf("%d",&t);
for(i=0;iscanf("%d",&a[i]);

for(i=0;i{
c=a[i];
while(palindrome(c)!=1)
c++;
printf("\n%d",c);
}
exit(1);
}

int palindrome(int n)
{
int i,j,key,*b;
i=0;
key=1;
while(n!=0)
{
b[i]=n%10;
n=n/10;
i++;
}
for(j=0;j<=i/2;j++)
{
if(b[j]==b[i-j-1])
continue;
else
{
key=0;
break;
}
}
return(key);
}

[system]

Is that the way of using pointers without initializing ?? Look at your code carefully and you will know.

[pandia]

I am sorry I didn't get you. I used to code in that way and It worked fine for me in turboc. Please correct my mistake.

[system]

Use gcc instead of turboc.
In your code you are using a[i] without initializing the pointer a. If still not getting me then you need to go through basics of array and pointers.

[pandia]

I never initialize a pointer and it worked fine so I never cared.
I tried initializing the pointer to NULL and 0, in either case it showed the same error.
I tried the same code declaring arrays as normal instead of a pointer and I land up with same error

[system]

If you are trying to solve any specific spoj problem please post the link. And post you new solution which uses normal array declaration( use code tags while posting code ).

[pandia]

This is the problem
spoj.pl/problems/PALIN/
and my code is

[code]

#include
int palindrome(int);

void main()
{
int a[10],c,t,i;
scanf("%d",&t);
for(i=0;iscanf("%d",&a[i]);

for(i=0;i{
c=a[i];
while(palindrome(c)!=1)
c++;
printf("\n%d",c);
}
exit(1);
}

int palindrome(int n)
{
int i,j,key,b[10];
i=0;
key=1;
while(n!=0)
{
b[i]=n%10;
n=n/10;
i++;
}
for(j=0;j<=i/2;j++)
{
if(b[j]==b[i-j-1])
continue;
else
{
key=0;
break;
}
}
return(key);
}
[/code]

when I run this code, I get runtime error (SIGSEGV)

[system]

You are taking a[10] and then t values are being stored in array. Declare array of size t.
Instead you can do like this :

main() 
{
scanf( "%d", &t );
while( t-- ) {
    scanf( "%d", &n );
   //process n .......... 
}
return 0;
}

[pandia]

How could I declare array of size t when t is an input parameter? And that is why I tried to used pointer instead of declaring an array.

[system]

If t is not very large int a[t] will work. But for large t you have to use malloc for memory allocation at run time. BTW i have already stated that you dont need to take the whole input together. Just take an input number, process it and print the result. Do this for all numbers.

[pandia]

if we declare a variable as a[t], I guess it gives a compilation error "constant expression required" . Secondly, if I process the variables one by one, I have to print them instantaneously and that is not the required output.

[system]

ideone.com/Iks3H : i dont see any compilation error here.
Which compiler are you using ??

if I process the variables one by one, I have to print them instantaneously and that is not the required output.

Its not true. Spoj judge first saves you whole output in a stream/file and then content of that stream is compared with actual output file. See the solution to TEST problem here : viewtopic.php?f=41&t=21. It will be clear to you.

[pandia]

oh!!, Thanks for your information.
I got a compilation error in turboc. I never used any other compiler other than tc and gcc.
Actually I am having an exam this weekend where they use computer judge. I am worried by seeing these errors:(