27.33 SortingPerm

SortingPerm( list )

SortingPerm returns the permutation that must be applied to list to sort it into ascending order.

    gap> list1 := [ 5, 4, 6, 1, 7, 5 ];;
    gap> list2 := Copy( list1 );;
    gap> perm := SortingPerm( list1 );
    (1,3,5,6,4)
    gap> list1;
    [ 5, 4, 6, 1, 7, 5 ]
    gap> Permuted( list2, perm );
    [ 1, 4, 5, 5, 6, 7 ] 

Sortex( list ) (see Sortex) returns the same permutation as SortingPerm( list ), and also applies it to list (in place).

Previous Up Top Next
Index