Algorithm to implement selection sort (ascending order):

SELECTIONSORTAO(arr,n)
Repeat For I =1 to n-1                [n-1 passes]
MIN <-- arr[I]
POS <-- I
Repeat for J=I+1 to n  [to select minimum element]
  If arr[J]< MIN Then:
     MIN <-- arr[J]
     POS <-- J
  [ End of if ]
 [ End of for J ]
 arr[pos] <-- arr[I]
 arr[I] <-- MIN
[End of For I ]
Exit.  

Algorithm to implement selection sort (descending order):

 SELECTIONSORTDO(arr,n)
[‘arr’ is an array of n elements]
Repeat For I =1 to n-1            
  MAX <-- arr[I]; POS <-- I
 Repeat for J=I+1 to n
   If arr[J]>MAX Then:
       MAX <-- arr[J];  POS <-- J
    [ End of if ]
   [ End of for J ]
   arr[pos] <-- arr[I];  arr[I] <-- MAX
[End of For I ]
Exit.