MATLAB: Sorting numbers in an array without sort function

arraybubblesorthomeworksort

Hello,
I want to sort numbers in an arrey without using sort function, but with bubblesort (swapping number next each other until all numbers are sorted)
Here is what I have…
X=[10 1 29 89 5 56 76 8];
finished=0;
while finished==0
    if finished==0
       for i=1:size(X,2)-1
          if X(i)>X(i+1)
              c=X(i);
              X(i)=X(i+1);
              X(i+1)=c;
          end
       end
   end
   if X(i)<X(i+1) || X(i)==X(i+1)
      finished=1; 
    end
end
disp(X)
I understand that this loop works by comparing numbers next each other (like comparing 10 with 1). Then, if the front number (10) is bigger than the next number (1), the numbers are swaped. However, I want to break the loop once all numbers are sorted from the minimum number to the maximum number.
The code above only sorts the numbers until [1,10,29,5,56,76,8,89], so I want to loop several more to complete the sorting, but I want the code stops when the sorting is done. Otherwise, the code keeps on looping again and again.
I really appreciate if I get some help with this problem.

Best Answer

Simply set your "finished" flag depending on whether a swap was done or not. E.g.,
while true
    finished = 1;
    for i=1:size(X,2)-1
        if X(i)>X(i+1)
            c=X(i);
            X(i)=X(i+1);
            X(i+1)=c;
            finished = 0;
        end
    end
    if finished
        break
    end
end
The for-loop can also be shortened by realizing that after each pass you are guaranteed to have one more element sorted at the bottom. I.e., the for-loop doesn't have to examine the entire array each time ... at each iteration you only have to examine one fewer elements.
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