AoC 2025 day 7 (dc)

# Command: perl -pe'print pos()." "while(m/[S^]/g);$_="\n"' <input | grep -v '^$' | dc -fdc-p12.dc

# Process Beam: beam -> 0 (num is passed in reg n)
[
    lp1+sp              # part1++
    d1+ d;t ln+ r:t     # table(beam+1) += num; beam
    d1- d;t ln+ r:t     # table(beam-1) += num; beam
    0 r:t               # table(beam) = 0
    0
] sB

? 1r:t                  # table(start)=1
?
[
    # split1 split2 ...
    [
        d;t dsn         # table(split) split ...
        0<B
        s.
        z0<L
    ] dsLx

    ? z0<M
] dsMx

[Part 1: ]n lpp

# Sum table for part 2
0*
F0                      # i sum
[
    d;t                 # table(i) i sum
    3R+ r               # i sum+=table(i)
    1- d0<L
] dsLx +

[Part 2: ]n p