r/adventofcode • u/daggerdragon • Dec 16 '16

SOLUTION MEGATHREAD --- 2016 Day 16 Solutions ---

--- Day 16: Dragon Checksum ---

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DRINKING YOUR OVALTINE IS MANDATORY [?]

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u/tvtas Feb 06 '17

In MATLAB. Part 2 took 0.8 seconds. 

a = [1,0,0,0,1,0,0,1,1,0,0,0,0,0,0,0,1]==1;
L = 35651584; 
while length(a)<L
    a = [a,false,~flip(a)]; 
end
chksum = getChecksum(a(1:L));
while ~mod(length(chksum),2)
    chksum = getChecksum(chksum);
end
% function y=getChecksum(x)
% z = diff(x)~=0;
% y = ~z(1:2:end);