Question

How do you take an array for example A = [4 6 7 1 2 5] and sort it from ascending order. So it would output A = [1 2 4 5 6 7]. In MATlab without using the sort function as well.

Answer 1

HI, Please find my implementation of selection sort.

%--------------------------------------------------------------------------
% Syntax: sx = selectionSort(x);
%   
% Inputs: x is a vector of length n
%   
% Outputs: sx is the sorted (ascending) version of x
%   
% Description: This function sorts the input array x in ascending order
% using the selection sort algorithm
%   
% Complexity: O(n^2) best-case performance
% O(n^2) average-case performance
% O(n^2) worst-case performance
% O(1) auxiliary space
%--------------------------------------------------------------------------

% Seletion sort

function x = selectionSort(x)
   n = length(x);
   for j = 1:(n - 1)
   % Find jth smallest element
   imin = j;
   for i = (j + 1):n
   if (x(i) < x(imin))
   imin = i;
   end
   end
  
   % Put jth smallest element in place
   if (imin ~= j)
   x = swap(x,imin,j);
   end
   end

end

% Swap x(i) and x(j)
% Note: In practice, x xhould be passed by reference

function x = swap(x,i,j)
   val = x(i);
   x(i) = x(j);
   x(j) = val;

end