AoC 2024, day 1, part 1 (dc)

# Command: dc -fdc-p1.dc <input

[q] sQ

# Read Input
?
[
    # stack: item2 item1
    d;b 1+ r:b          # b(item2)++
    d;a 1+ r:a          # a(item1)++
    ? z0<I
] dsIx

# sorting loop, paramertized (lGx: get from reg array, lPx: push to reg stack)
[
    99999
    [
        dlGx            # j=get(i) i
        [
            d 0=Q       # j i, quit if j == 0
            rd lPx r    # Push copy of i on register stack
            1- lJx      # j--
        ] dsJx +        # end: junk j=0 with addition
        1- d0<I         # i--, loop while i > 0
    ] dsIx
] sS

0 Sc                    # add sentinel to bottom of c
[;a]sG [Sc]sP lSx       # convert array a into sorted stack c
[;b]sG [Sd]sP lSx       # convert array b into sorted stack d

# Process
0                       # sum
[
    Lc d0=Q             # pop item, quit if == 0
    Ld - d*v +          # sum += abs(item1 - item2)
    lLx
] dsLx

[Part 1: ]nrp