clc;clear;close all

tic
disp('starting')
fid     = fopen('input.txt','r');


% Check for type of values, number of robots and outputs: value > 0, 210 bots and 20 outputs

allbots=[];
alloutputs=[];
allvalues=[];
instrList={};

while 1
    str = fgetl(fid);
    if str==-1
        break
    else
        instrList{end+1,1} = str;
        if strfind(str,'value')
            A = sscanf(str,'value %i goes to bot %i');
            allvalues=[allvalues,A(1)];
            allbots=[allbots,A(2)];
        else
            A1 = sscanf(str,'bot %i gives low to bot %i and high to bot %i');
            if length(A1)==3
                allbots=[allbots,A1(2)];
                allbots=[allbots,A1(3)];
            end
            A2 = sscanf(str,'bot %i gives low to output %i and high to bot %i');
            if length(A2)==3
                allbots=[allbots,A2(3)];
                alloutputs=[alloutputs,A2(2)];
            end

            A3 = sscanf(str,'bot %i gives low to bot %i and high to output %i');
            if length(A3)==3
                allbots=[allbots,A3(2)];
                alloutputs=[alloutputs,A3(3)];
            end

            A4 = sscanf(str,'bot %i gives low to output %i and high to output %i');
            if length(A4)==3
                alloutputs=[alloutputs,A4(2)];
                alloutputs=[alloutputs,A4(3)];
            end

        end
    end
end


allvalues = unique(allvalues)';
allbots = unique(allbots)' ;
alloutputs = unique(alloutputs)' ;

B = zeros(length(allbots),2);
O = zeros(length(alloutputs),1);

% Loop through instructions: 1st loop assign only values
for i=1:size(instrList,1)
    str = instrList{i,1};
    if strfind(str,'value')
        A = sscanf(str,'value %i goes to bot %i');
        A(2)=A(2)+1; % zero indexing
        B = giveBotValue(B,A(2),A(1));
    else % fill other instruction list
        A = sscanf(str,'bot %i gives');
        giveInstr{A+1,1}=str;
    end
end

% main loop:
while any(sum(B>0,2)==2)

    idx=find(sum(B>0,2)==2);
    idx=idx(1);

    if B(idx,1)==17 && B(idx,2)==61
        disp('Bot found')
        idx-1 %answer part A
    end
    str = giveInstr{idx,1};

    A1 = sscanf(str,'bot %i gives low to bot %i and high to bot %i');
    if length(A1)==3
        A1=A1+1; % zero indexing
        if B(A1(1),1) && B(A1(1),2) % do nothing if robot is not full
            lowval  =  B(A1(1),1);
            highval =  B(A1(1),2);
            B(A1(1),1) = 0;
            B(A1(1),2) = 0;
            B = giveBotValue(B,A1(2),lowval);
            B = giveBotValue(B,A1(3),highval);
        end
    end
    A2 = sscanf(str,'bot %i gives low to output %i and high to bot %i');
    if length(A2)==3
        A2=A2+1; % zero indexing
        if B(A2(1),1) && B(A2(1),2) % do nothing if robot is not full
            lowval  =  B(A2(1),1);
            highval =  B(A2(1),2);
            B(A2(1),1) = 0;
            B(A2(1),2) = 0;
            O(A2(2)) = lowval;
            B = giveBotValue(B,A2(3),highval);
        end
    end

    A3 = sscanf(str,'bot %i gives low to bot %i and high to output %i');
    if length(A3)==3
        A3=A3+1; % zero indexing
        if B(A3(1),1) && B(A3(1),2) % do nothing if robot is not full
            lowval  =  B(A3(1),1);
            highval =  B(A3(1),2);
            B(A3(1),1) = 0;
            B(A3(1),2) = 0;
            O(A3(3)) = highval;
            B = giveBotValue(B,A3(2),lowval);
        end
    end

    A4 = sscanf(str,'bot %i gives low to output %i and high to output %i');
    if length(A4)==3
        A4=A4+1; % zero indexing
        if B(A4(1),1) && B(A4(1),2) % do nothing if robot is not full
            lowval  =  B(A4(1),1);
            highval =  B(A4(1),2);
            B(A4(1),1) = 0;
            B(A4(1),2) = 0;
            O(A4(2)) = lowval;
            O(A4(3)) = highval;
        end
    end
end

O(1)*O(2)*O(3) % %answer part B
disp('finished')
toc

function B = giveBotValue(B,idx,v)

if B(idx,1)>0
    if B(idx,2)>0
        error('Bot full, cannot assign new idxalue')
    else
        if v>=B(idx,1)
            B(idx,2)=v;
        else
            B(idx,2)=B(idx,1);
            B(idx,1)=v;
        end
    end
else
    if B(idx,2)>0
        if v>=B(idx,2)
            B(idx,1)=B(idx,2);
            B(idx,2)=v;
        else
            B(idx,1)=v;
        end
    else
        B(idx,1)=v;
    end
end
end