--- Begin Message ---
Oke
Maybe it is better to give the whole challenge
On the way to your gravity
assist around the Moon, your ship computer beeps angrily
about a "1202
program alarm". On the radio, an Elf is already explaining
how to handle the situation: "Don't worry, that's perfectly
norma--" The ship computer bursts
into flames.
You notify the Elves that the computer's magic smoke
seems to have escaped. "That computer
ran Intcode programs like the gravity assist program
it was working on; surely there are enough spare parts up there
to build a new Intcode computer!"
An Intcode program is a list of integers
separated by commas (like 1,0,0,3,99). To run one,
start by looking at the first integer (called position 0).
Here, you will find an opcode - either 1,
2, or 99. The opcode indicates what
to do; for example, 99 means that the program is
finished and should immediately halt. Encountering an unknown
opcode means something went wrong.
Opcode 1 adds together numbers read
from two positions and stores the result in a third position.
The three integers immediately after the opcode tell
you these three positions - the first two indicate the positions
from which you should read the input values, and the third
indicates the position at which the output should be
stored.
For example, if your Intcode computer encounters 1,10,20,30,
it should read the values at positions 10 and 20,
add those values, and then overwrite the value at position 30
with their sum.
Opcode 2 works exactly like opcode 1,
except it multiplies the two inputs instead of adding
them. Again, the three integers after the opcode indicate where
the inputs and outputs are, not their values.
Once you're done processing an opcode, move to the next
one by stepping forward 4 positions.
For example, suppose you have the following program:
1,9,10,3,2,3,11,0,99,30,40,50
For the purposes of illustration, here is the same program
split into multiple lines:
1,9,10,3,
2,3,11,0,
99,
30,40,50
The first four integers, 1,9,10,3, are at
positions 0, 1, 2, and
3. Together, they represent the first opcode (1,
addition), the positions of the two inputs (9 and 10),
and the position of the output (3). To handle this
opcode, you first need to get the values at the input positions:
position 9 contains 30, and position
10 contains 40. Add these
numbers together to get 70. Then, store this value
at the output position; here, the output position (3)
is at position 3, so it overwrites
itself. Afterward, the program looks like this:
1,9,10,70,
2,3,11,0,
99,
30,40,50
Step forward 4 positions to reach the next
opcode, 2. This opcode works just like the
previous, but it multiplies instead of adding. The inputs are at
positions 3 and 11; these positions
contain 70 and 50 respectively.
Multiplying these produces 3500; this is stored at
position 0:
3500,9,10,70,
2,3,11,0,
99,
30,40,50
Stepping forward 4 more positions arrives at
opcode 99, halting the program.
Here are the initial and final states of a few more small
programs:
1,0,0,0,99 becomes 2,0,0,0,99
(1 + 1 = 2).
2,3,0,3,99 becomes 2,3,0,6,99
(3 * 2 = 6).
2,4,4,5,99,0 becomes 2,4,4,5,99,9801
(99 * 99 = 9801).
1,1,1,4,99,5,6,0,99 becomes 30,1,1,4,2,5,6,0,99.
Once you have a working computer, the first step is to restore
the gravity assist program (your puzzle input) to the "1202
program alarm" state it had just before the last computer caught
fire. To do this, before running the program, replace
position 1 with the value 12 and
replace position 2 with the value 2.
What value is left at position 0 after
the program halts?
so as you can see in the tests there are no data changed so my
code works fine and all the tests are green but when you want to
work with the real data the say that you have to replace two
values.
So my question is how to make that part work without breaking
the tests.
Roelof
Op 28-12-2019 om 21:46 schreef Sean P. DeNigris:
Pharo Smalltalk Users mailing list wrote
so to be clear. In the test are data given which not has to be changed. As
soon as you have to solve the real problem , some data needs to be
changed.
It's difficult to give good design advice with such a
