Breaking_Bar(action)

function Breaking_Bar(action)
%----------------------------------------------------------------------
%INTRODUCTION:
%Assume you have a chocolate bar (M x N) consisting of number of squares
%arranged in a rectangular pattern. Your task is to split the bar into small
%squares (always breaking along the lines between the squares) with a minimum
%number of breaks. How many will it take?

%ANSWER: "M+N-1" (Unique Solution, hence NO Optimum Solution)
%----------------------------------------------------------------------
global fig M N BrBa msgdisp barbreak BrBa_store game_hand break_hand;
clc;
%----------------------------------------------------------------------
if nargin < 1, 
    M=3+mod(fix(10*rand(1,1)),2);  
    N=3+mod(fix(10*rand(1,1)),2);
    BrBa=ones(2*M-1,2*N-1);
    
    for ii=1:2*M-1
        for jj=1:2*N-1
            %Chocolate Pieces
            if (mod(ii,2)==1 && mod(jj,2)==1),  BrBa(ii,jj)=2;  end
            %Intersection Points or Junction Points
            if (mod(ii,2)==0 && mod(jj,2)==0),  BrBa(ii,jj)=1;  end
        end
    end   
    
    msgdisp=1;
    barbreak=0;
    action='Start';    
end
%--------------------------------------------------------------------------
if strcmp(action,'Start')
    fig=figure( ...
                'Name','Breaking Chocolate Bar', 'NumberTitle','off', ...
                'Visible','off', 'BackingStore','off','units','normalized');             
    
    %----------------------------------------------------------------------
    % Handling the handles
            
    game_hand=uicontrol('units','normalized','position',[.3 .04 .07  .05],...
                'string','Game','callback','Breaking_Bar(''MathModel'')',...
                'interruptible','on','BackgroundColor',[1 0 0]);
            
    uicontrol('units','normalized','position',[.4 .04 .07  .05],...
                'string','Help','callback','Breaking_Bar(''Help'')',...
                'interruptible','on','BackgroundColor',[1 0.5 0.2]);
            
    uicontrol('units','normalized','position',[.5 .04 .07  .05],...
                'string','Reset','callback','Breaking_Bar(''Reset'')',...
                'interruptible','on','BackgroundColor',[1 0.5 0.2]);

    uicontrol('units','normalized','position',[.6 .04 .07  .05],...
                'string','Exit','callback','delete(gcf)',...
                'interruptible','on','BackgroundColor',[1 0.5 0.2]);
      
    %drawing Chocolate Pieces        
    for ii=1:N,
        for jj=1:M,
            chocolate(ii-0.5,jj-0.5);
        end
    end
    rectangle('Position', [0 0 N M],'linewidth',0.25,'edgecolor',[0.7 0.7 0.7]);
    
    text(0.5*N-0.5,M+0.2,'Breaks:','color',[0.8 0.3 0.3],'fontsize',10,'fontweight','bold');
    break_hand=text(0.5*N+0.25,M+0.2,sprintf('%d',barbreak),'color',[0.8 0.1 0.1],'fontsize',10,'fontweight','bold');
    
    figure(fig);     
    
    if msgdisp==1,
        msg={'click "Game" button to start the Game...'};
        msg_handle=msgbox(msg,'Breaking Chocolate Bar!','help');
        if ~waitforbuttonpress,  close(msg_handle);  end
    end
end
%--------------------------------------------------------------------------
if strcmp(action,'Reset') 
    closereq;
    Breaking_Bar();
end
%--------------------------------------------------------------------------
if strcmp(action,'MathModel')
    set(game_hand,'BackgroundColor',[1 0.5 0.2]);
    while (barbreak~=M*N-1),
%     while (length(find(BrBa==0))~=(M-1)+(N-1)),
        %(M-1)+(N-1)+(M-1)*(N-1)
        validpt=[0 0];
        set(fig,'Currentpoint',[0 0]);
        while (validpt(1)==0 && validpt(2)==0),
            validpt = get(fig,'Currentpoint');
            row=validpt(1); col=validpt(2);            
            pause(1);
        end        
                
        x=row*(N+1);    y=col*(M+1);        
        r=round(x);     c=round(y);

        if abs(x-r) < abs(y-c),  Opt=1;  end
        if abs(x-r) > abs(y-c),  Opt=2;  end
        if abs(x-r) == abs(y-c),  Opt=1+mod(fix(10*rand(1,1)),2);  end
        
        if x < r,  r=r-1;  end
        if y < c,  c=c-1;  end
        
        row=c;  col=r;
                
        if Opt==1,  row=2*row;    col=2*col-1;  end
        if Opt==2,  row=2*row-1;  col=2*col;    end

        valid=0; 
        if (row>0 && row<2*M && col>0 && col<2*N),  valid=1; end        
        for ii=1:barbreak,
             if (BrBa_store(ii,1)==row && BrBa_store(ii,2)==col), 
                  valid=0; 
             end
        end
        
        if valid==0,
            [valid,row,col]=heuristic(BrBa_store,barbreak,M,N,row,col);
            if mod(row,2)==0,  Opt=1;  end
            if mod(col,2)==0,  Opt=2;  end
        end
        
        if valid==0,  
            continue;  %invalid step 
        else    
            BrBa_bkp=BrBa;
            BrBa=Update_Bar(Opt,row,col,BrBa);
            if BrBa_bkp==BrBa,  continue;  end
            BrBa_bkp=BrBa;
            barbreak=barbreak+1;
            BrBa_store(barbreak,:)=[row col];
            
            %Updating Math Model Matrix
            for ii=1:2*M-1
                for jj=1:2*N-1
                    %Chocolate Pieces
                    if (mod(ii,2)==1 && mod(jj,2)==1),  BrBa(ii,jj)=2;  end
                    %Intersection Points or Junction Points
                    if (mod(ii,2)==0 && mod(jj,2)==0),  BrBa(ii,jj)=1;  end
                end
            end

            Update_Board(M,N,BrBa);
            set(break_hand,'string',barbreak);
            BrBa=BrBa_bkp;
        end
    end
    
    pause(2);
    [namastedata namastemap]=imread('namaste.jpg');
    msg={'Good Try...!'};
    msg_handle=msgbox(msg,'Breaking Chocolate Bar','custom',namastedata,namastemap);        
    pause(3);
    close(msg_handle);
    closereq;
end
%--------------------------------------------------------------------------
if strcmp(action,'Help')
    msg={'DESCRIPTION of GAME:                                               ',...
         '                                                                   ',... 
         '1. Use the intersection lines to break the chocolate bar.          ',...                
         '2. At any instant only single solid piece is allowed to break.     ',...
         '3. The objective is to minimize breaks to obtain individual pieces.'}; 
    msgbox(msg,'Breaking Bar','help');
end
%--------------------------------------------------------------------------