Write a MATLAB program which implements the BubbleSort algor

Write a MATLAB program which implements the Bubble-Sort algorithm. Show progress of the sorting. Demonstrate with a 20 element vector having random element vlaues.

Then,

Improve the Bubble Sort algorithm so that it detects if a vector is already sorted.

Demonstrate with a 20 element vector having random element vlaues.

Solution

In order to make it easier, you can generate the code by using several functions. What is more, in order to improve the system we can use a function that, before running the Bubble-sort algorithm, verifies whether the vector is already sorted.

- Verify function:

function [c] = verify(v)
c=0; %it is ordered
for i=1:length(v)-1
if v(i)>v(i+1)
c=1; % disordered
break % the loop ends
end
end
end

Now, in case that the vector is not sorted, the Bubble-Sort algorithm has to be run. However, it implies the swapping among the vector elements (in order to sort the vector). Therefore, the following function may be used:

- Swapping function

function [r] = swap(a,b)
if a>b
r(1)=b;
r(2)=a;
else
r(1)=a;
r(2)=b;
end
end

Finally, the Bubble-Sort algorithm can be applied by using the following code:

- Bubble-sort function

function [x] = bubblesort(v)
z=v;
c=verify(z); %Function shown above
while c==1 % If the vector is not sorted, the bubble-Sort algorithm is run
for i=1:length(z)-1
if z(i) > z(i+1)
x=swap(z(i),z(i+1)); %Function shown above
z(i)=x(1); %Assigning the result of the swap function
z(i+1)=x(2);
end
end
c=verify(z);
end
x=z; %Final vector - answer
end

Demonstration:

v = randi([0 300],1,20); % generating random integers values from 0 to 300 and putting them in an array that has the components from 1 to 20 (20 element vector)

Resulting the following vector:

v =

Columns 1 through 15

245 272 38 274 190 29 83 164 288 290 47 292 288 146 240

Columns 16 through 20

42 126 275 238 288

Applying the designed function:

>> y=bubblesort(v)

y =

Columns 1 through 15

29 38 42 47 83 126 146 164 190 238 240 245 272 274 275

Columns 16 through 20

288 288 288 290 292

Getting the expected solution.

NOTE:
In order to show the progess of the sorting the only thing that has to be done is this:(in the code of the Bubble-sort function):

function [x] = bubblesort(v)
z=v;
c=verify(z);
while c==1
for i=1:length(z)-1
if z(i) > z(i+1)
x=swap(z(i),z(i+1));
z(i)=x(1);
z(i+1)=x(2);
end
end
display(z); % The vector is going to be shown in every loop, showing the progress of the sorting
c=verify(z);
end
x=z;
end