Annotated assembler code, program translated to python.
Aliases used in pseudocode & python shown in parenthesis.
r0 (r) - result accumulator
r1 (x) - inner counter
r2 - temporary values
r3 (n) - target value for counters
r4 - instruction pointer
r5 (y) - outer counter
0 addi 4 16 4 # JMP 17
### Calculate result
1 seti 1 2 5 # r5 = 1 | y = 1
2 seti 1 1 1 # r1 = 1 | x = 1
3 mulr 5 1 2 # r2 = r5 * r1 \
4 eqrr 2 3 2 # r2 = (r2 == r3) ? 1 : 0 | if (y * x) == n:
5 addr 2 4 4 # JMP +r2 | result += y
6 addi 4 1 4 # JMP +1 |
7 addr 5 0 0 # r0 = r5 + r0 /
8 addi 1 1 1 # r1 = r1 + 1 | x += 1
9 gtrr 1 3 2 # r2 = (r1 > r3) ? 1 : 0 \
10 addr 4 2 4 # JMP +r2 | if x <= n: JMP 3
11 seti 2 4 4 # JMP 3 /
12 addi 5 1 5 # r5 = r5 + 1 | y += 1
13 gtrr 5 3 2 # r2 = (r5 > r3) ? 1 : 0 \
14 addr 2 4 4 # JMP +r2 | if y <= n: JMP 2
15 seti 1 8 4 # JMP 2 /
16 mulr 4 4 4 # JMP 256 | HALT
### Initial setup
17 addi 3 2 3 # r3 = r3 + 2 \
18 mulr 3 3 3 # r3 = r3 * r3 | (assuming r2 = r3 = 0)
19 mulr 4 3 3 # r3 = r4 * r3 = 19 * r3 |
20 muli 3 11 3 # r3 = r3 * 11 | r3 = 11 * 19 * (r3 + 2)^2 + 22 * (r2 + 4) + 6
21 addi 2 4 2 # r2 = r2 + 4 | = 11 * 19 * 4 + 22 * 4 + 6
22 mulr 2 4 2 # r2 = r2 * r4 = r2 * 22 | = 930
23 addi 2 6 2 # r2 = r2 + 6 |
24 addr 3 2 3 # r3 = r2 + r3 /
25 addr 4 0 4 # JMP +r0 | if r0 == 0: (part 1)
26 seti 0 8 4 # JMP 1 | JMP 1
27 setr 4 1 2 # r2 = r4 = 27 \
28 mulr 2 4 2 # r2 = r2 * r4 = 27 * 28 = 756 |
29 addr 4 2 2 # r2 = r4 + r2 = 29 + 756 = 785 |
30 mulr 4 2 2 # r2 = r4 * r2 = 30 * 785 = 23550 | r3 = r3 + 10550400
31 muli 2 14 2 # r2 = r2 * 14 = 23550 * 14 = 329700 | = 930 + 10550400
32 mulr 2 4 2 # r2 = r2 * r4 = 329700 * 32 = 10550400 | = 10551330
33 addr 3 2 3 # r3 = r3 + r2 = r3 + 10550400 /
34 seti 0 0 0 # r0 = 0 | clear r0 (used to store the result)
35 seti 0 0 4 # JMP 1 | go to calculation
The inital setup populates r3 (alias n) to 930 for part 1 and to
10551330 for part 2.
The calculation contains two nested loops where:
- outer counter y goes 1..(n + 1)
- inner counter x goes 1..(n + 1)
At any point, if x * y == n, y is added to the result.
n = 930
if part2:
n += 10550400
r = 0
for x in range(1, n + 2):
for y in range(1, n + 2):
if x * y == n:
r += y
print(r)The condition is true if x and y are factors of n. Therefore this program returns a sum of all factors of n.