circuit.m

function circuit(s, t, E)

    % numeracja rezystorow wedle kolejnosci na wejsciu
    % zalozenie, ze zaden nie zostanie podany dwa razy

    A = importdata('graf.txt');
    [t1, ~] = size(A);
    A(t1+1,1) = s;
    A(t1+1,2) = t;
    A(t1+1,3) = -1 * abs(E);

    [x1, ~] = size(A);

    numG = 0; % liczba wierzcholkow

    for i=1:x1
        for j=1:2
            numG = max(numG, A(i,j));
        end
    end

    % G(i,j) - opory pomiedzy punktami (i,j)
    G = zeros(numG, numG);

    % gr = graph;

    % wczytanie danych do macierzy sasiedztw wazonych
    for i=1:x1
        G(A(i,1), A(i,2)) = A(i,3);
        G(A(i,2), A(i,1)) = A(i,3);
        % gr = addedge(gr, A(i,1), A(i,2), A(i,3));
    end

    % plot(gr);

    disp(G);

    mI = [];
    mE = [];

    for i=1:numG
        if i ~= s && i ~= t
            for j=1:numG
                % prad plynie z mniejszego numerem wezla do wiekszego
                % numerem wezla
                if G(i,j) > 0
                    if j>i
                        mI(i,edge_id(A,i,j)) = 1; % G(i,j);
                    else
                        mI(i,edge_id(A,i,j)) = -1 % * G(i,j);
                    end
                    mE(i) = 0;
                end
            end
        end
    end

    disp(mI);
    disp(mE);

    edgeMap = A( : , 1:2 );
    cyclelist = searchCycles(edgeMap);

    cyclecount = length(cyclelist);

    [offset, ~] = size(mI);

    for i=1:cyclecount
        mE(i+offset) = 0;

        for j=1:length(cyclelist{i})
            path = cyclelist{i};
            first_node = path(j);
            if j == length(cyclelist{i})
                second_node = path(1); % zawrotka na poczatek listy
            else
                second_node = path(j+1);
            end

            if G(first_node,second_node) > 0
                 if second_node>first_node
                    mI(i+offset,edge_id(A,first_node,second_node)) = G(first_node,second_node);
                 else
                    mI(i+offset,edge_id(A,first_node,second_node)) = -1 * G(first_node,second_node);
                 end
            end

            if G(first_node,second_node) < 0
                if first_node == s
                    mE(i+offset) = E;
                else
                    mE(i+offset) = -E;
                end
            end
        end
    end

    [XX, R] = linsolve(mI, mE.');
    XX

    circ = graph;

    for i=1:t1
        circ = addedge(circ, A(i,1), A(i,2), abs(XX(i)));
    end

    % krawedz nie moze miec grubosci zero, stad 1e-10 dodane do kazdej
    % grubosci krawedzi

    LWidths = 5*(circ.Edges.Weight+1e-10)/max(circ.Edges.Weight);
    plot(circ,'EdgeLabel',circ.Edges.Weight,'LineWidth',LWidths)
end