% Start with 3 missionaries and 3 cannibals and the boat on the left side.
start = [3 3 1]
s1 = generate(start);
goal_reached(s1); % Test if goal has been reached.
s2 = generate(unique(s1,"rows")(:,1:3));
goal_reached(s2);
s3 = generate(unique(s2,"rows")(:,1:3));
goal_reached(s3);
s4 = generate(unique(s3,"rows")(:,1:3));
goal_reached(s4);
s5 = generate(unique(s4,"rows")(:,1:3));
goal_reached(s5);
s6 = generate(unique(s5,"rows")(:,1:3));
goal_reached(s6);
s7 = generate(unique(s6,"rows")(:,1:3));
goal_reached(s7);
s8 = generate(unique(s7,"rows")(:,1:3));
goal_reached(s8);
s9 = generate(unique(s8,"rows")(:,1:3));
goal_reached(s9);
s10 = generate(unique(s9,"rows")(:,1:3));
goal_reached(s10);
s11 = generate(unique(s10,"rows")(:,1:3));
goal_reached(s11);

% Now backtrack to get the steps
if goal_reached(s11)
 steps = zeros(1,3);
 r = all(s11(:,1:3) == 0,2);
 last_steps = s11(r,:);

 last_states = last_steps(:,5:7);
 steps(2,:) = last_states(1,:);
 %if size(last_states,1) > 1
   for i = 1:size(last_states,1)
     r = all(s10(:,1:3) == last_states(i,:),2);
     last_steps = s10(r,:);
   end
 %end

 last_states = last_steps(:,5:7);
 steps(3,:) = last_states(1,:);
 %if size(last_states,1) > 1
   for i = 1:size(last_states,1)
     r = all(s9(:,1:3) == last_states(i,:),2);
     last_steps = s9(r,:);
   end
 %end

 last_states = last_steps(:,5:7);
 steps(4,:) = last_states(1,:);
 %if size(last_states,1) > 1
   for i = 1:size(last_states,1)
     r = all(s8(:,1:3) == last_states(i,:),2);
     last_steps = s8(r,:);
   end
 %end

 last_states = last_steps(:,5:7);
 steps(5,:) = last_states(1,:);
 %if size(last_states,1) > 1
   for i = 1:size(last_states,1)
     r = all(s7(:,1:3) == last_states(i,:),2);
     last_steps = s7(r,:);
   end
 %end

 last_states = last_steps(:,5:7);
 steps(6,:) = last_states(1,:);
 %if size(last_states,1) > 1
   for i = 1:size(last_states,1)
     r = all(s6(:,1:3) == last_states(i,:),2);
     last_steps = s6(r,:);
   end
 %end

 last_states = last_steps(:,5:7);
 steps(7,:) = last_states(1,:);
 %if size(last_states,1) > 1
   for i = 1:size(last_states,1)
     r = all(s5(:,1:3) == last_states(i,:),2);
     last_steps = s5(r,:);
   end
 %end

 last_states = last_steps(:,5:7);
 steps(8,:) = last_states(1,:);
 %if size(last_states,1) > 1
   for i = 1:size(last_states,1)
     r = all(s4(:,1:3) == last_states(i,:),2);
     last_steps = s4(r,:);
   end
 %end

 last_states = last_steps(:,5:7);
 steps(9,:) = last_states(1,:);
 %if size(last_states,1) > 1
   for i = 1:size(last_states,1)
     r = all(s3(:,1:3) == last_states(i,:),2);
     last_steps = s3(r,:);
   end
 %end

 last_states = last_steps(:,5:7);
 steps(10,:) = last_states(1,:);
 %if size(last_states,1) > 1
   for i = 1:size(last_states,1)
     r = all(s2(:,1:3) == last_states(i,:),2);
     last_steps = s2(r,:);
   end
 %end

 last_states = last_steps(:,5:7);
 steps(11,:) = last_states(1,:);
 %if size(last_states,1) > 1
   for i = 1:size(last_states,1)
     r = all(s1(:,1:3) == last_states(i,:),2);
     last_steps = s1(r,:);
   end
 %end

 last_states = last_steps(:,5:7);
 steps(12,:) = last_states(1,:);
 %if size(last_states,1) > 1
   for i = 1:size(last_states,1)
     r = all(start(:,1:3) == last_states(i,:),2);
     last_steps = start(r,:);
   end
 %end

 flipud(steps)
end