% Section 3 Solutions


% --------------------
% #1  Basic Fibonacci:  Print F(1), F(2), ..., F(n)
%
n= input('Input n: ');
value1= 1;
value2= 1;
fib= 0;

if (n >= 1)
    if (n == 1)
        fprintf('%d ', value1);
    elseif (n == 2)
        fprintf('%d %d ', value1, value2);
    else
        for i=3:n
            fib= value1 + value2;
            value1= value2;
            value2= fib;
            fprintf('%d ', value2);
        end
    end
    disp(' ');
else
    disp('Must input number > 0');
end



% --------------------
% #2 Advanced Fibonacci (consecutive--not nested--loops)
% Print all integers from F(n) to F(n+1), inclusive
%
n= input('Input n: ');
value1= 1;
value2= 1;

if (n >= 1)
    if (n == 1)
        fprintf('%d ', value1)
    elseif (n==2)
	fprintf('%d %d ', value2, value1+value2)
    else
        for i=3:n+1
            fib = value1 + value2;
            value1 = value2;
            value2 = fib;
	    % At this point, value2 is F(i) and value 1 is F(i-1)
        end
        
        for i=value1:value2
            fprintf('%d ', i);
        end
    end
    disp(' ');
else
    disp('Must input number > 0');
end



% --------------------
% #3 Factors of n

n= input('Input n: ');

if (n >= 1)
    for i=2:n-1
        if (mod(n,i) == 0)
            fprintf('%d ', i);
        end
    end
    disp(' ');
else
    disp('Must input number > 0');
end


% --------------------
% #4 Factors of n.  Use WHILE loop instead of for-loop

n= input('Input n: ');

if (n >= 1)
   i= 2;
   while (i<n) 
      if (mod(n,i) == 0)
            fprintf('%d ', i);
      end
   end
   disp(' ');
else
   disp('Must input number > 0');
end


% -----------------------------
% Challenge: Prime Factors of n
%

n= input('Input n: ');

if (n >= 1)
    for i=2:n-1
        if (mod(n,i) == 0)
            j= 2;
            while  (mod(i,j) ~= 0 && j <= i)
                j = j + 1;
            end
            if (j == i)
                fprintf('%d ', i);
            end
        end
    end
    disp(' ');
else
    disp('Must input number > 0');
end