Question

I need to add leading zeros to an array for mathematical use.
Specifically, I am making something to add two large numbers. The numbers are stored as an int array, where each element of the array is 5 digits. One example is
53498 93784 45891 45982 48933 58947
I need to add another to this, say,
23584 42389 32479 34289 39281 48237
To add them I would take the last 5 digits of both and add them 58947+48237
This gives 107184. Then I set the carry value to 1 and subtract 100,000.

This is the problem:
It sets the int to 7184, then the sum says …882157184 instead of 8821507184, making a (very) incorrect sum.
So how do I get my Sum int array to say 88215 07184?
If this is not possible, please list another way of getting the same result, maybe a string instead of a int array?
If at all possible, please try to find a way to have a leading 0 with an int value.

Answer 1

Have you considered using Java’s BigInteger class?

• Large Numbers in Java

• Java Big Integers

• Java, comparing BigInteger values

• Converting from Integer, to BigInteger

e.g.

BigInteger quiteBig = new BigInteger("534989378445891459824893358947");