AoC 2025, day 6 part 1 (dc)

# Command: perl -pe's#([+*])#[$1]#g' <input | dc -fdc-p1.dc

[ sS ?[lSx z1<M] dsMx ] sL

0
[SA] lLx [SB] lLx [SC] lLx [SD] lLx
[SO] lLx

A00                 # i=n sum
[
    LDLCLBLA LOdd   # op op op num1 num2 num3 num4 i sum
    _5R _6R         # op num1 num2 op num3 op num4 i sum
    x rx rx         # result i sum
    3R+             # sum += result
    r1- d0<M
] dsMx

[Part 1: ]n rp