Little C++ Help - convert int to int[]

[falconfighter]

One of my projects for class is to write a program to make a number into a palindrome by adding the reverse of a number to it, i.e.
512 +
215
----
727 == palindrome

I am thinking of writing a function to reverse an array, then convert back then add, so something like
int a = 512;
int old[3];
int new[3];
old = inttoarray(a);
for(int loop = 0; loop <length(a); loop++)
{
new[loop] = old[length(a)-loop]
}
return a+arraytoint(new);

the lynchpin is, I have to find a way to convert int to int array and back again, and I have no idea. I've had a look at stringstreams, but I'm trapped in visual C++ 6, and it doesn't seem to work. Any ideas?

 

[mundane]

Have you learned about the % (mod) operator yet? You could leverage it to do the conversion you want.

 

[falconfighter]

I knew about it, but I have no idea how it would work in this situation. I think I can do the arraytoint() function, but the inttoarray just mystifies me.

 

[DaveSimmons]

Say you want to pick apart "127"

what is the result of 127 % 10?

what is the result of 12 % 10?

what is the result of 1 % 10?

Have you learned about "while" loops yet?

 

[sao123]

theres two ways to do it....

you could do this...

[5] * 100 + [1] * 10 + [2] * 1 = 512
[2] * 100 + [1] * 10 + [5] * 1 = 215

but then you have to get the 727 back into an array using divide & mod...


OR

it seems easier to me to just create a function

void array_adder(int[size], int[size], int[size+1]);

performs this function:
[5][1][2]
[2][1][5]
=======
[7][2][7]

[2] + [5] = [7]
[1] + [1] = [2]
[5] + [2] = [7]

and it goes right into the array.
The only pitfall is you have to beware of carry overs, but thats not hard to program.

 

[itachi]

when your assignment is graded, is it going to be compiled in vc6? if not, get a different stl - either stlport or stdcxx. both are a hell of a lot more compliant than the vc6 stl. otherwise, use sprintf/snprintf.

either instance, convert the integer to a string, and swap the digits. the simplest way would be to print the string in reverse order into a seperate string and call atoi.