jorritolthuis/integer-arithmetic

First integer arithmetic assignment for the TU/e course 2WF90

integer-arithmetic's Issues

Carry bug

Currently it only possible to have a carry of 1. In theory we could have D+E (hexadecimal) as input. This would convert to 13+14 = 27 (carry of 2). Hence, our result will be 11 whereas the answer should be 1B.

Karatsuba output is incorrect

The output of multiply, add and subtract are correct. This means there must be a mistake in the method of Karatsuba itself.

Substracting a big positive number from a small positive number

When substracting numbers and the answer should get negative; it does return a bullshit answer.
Input:

[radix] 10
[subtract]
[x] 2300
[y] 4100
# [answer] -1800

Output:

# [x] 2300
# [subtract] with radix 10
# [y] 4100

# [result] 18200

NullPointerException in Add

When giving multiple inputs to Add, a NullPointerException is triggered at the first if-statement (i.e. x or y seems null).
I am not sure if this is caused by commit b16e1fe.

Comments in Add

The Add class can use some more comments, to me it's not clear what happens.

Add comments to Add and Subtract

Add some comments to improve readability of code as requested by the assignment.

Copying remaining part of the string

Copying remaining part goes wrong on two part:

if there isn't a carry or when there is a carry but next number is the highest number in the base

Error in adding positive and negative number

When running Karatsuba, there is an instance at which it needs to add 1000 and -00100 in radix 2. It calls subtract after which an error is thrown.

Edit: The line numbers of Karatsuba might have shifted

Input: (or just giving -f ./test/example.txt as argument when running)

[radix] 2 
[karatsuba]
[x] 1111001110011011011101001100010101111000011010100100001101011101111101101110010001111010001010110011
[y] 1110110000001110100000101100010100101010110001101100011011101000101001001001000100001111010100100110
# [answer] 11100000101000010001111010010110111111100111000001010111101100100100001100000010011011111001001001111100000010010100100011101011001011000101101001100010110001000001001000100011100001110111010110010010

Directly giving the following input as command also results in the same error: (is the reduced version of the problem)

[radix] 2
[add]
[x] 1000
[y] -00100
end

Multiple inputs in one file

example.txt shows that it is possible to have multiple inputs in one file. How are we going to handle that?
example.txt