CL-USER> (time (let ((top-10 '(0 0 0 0 0 0 0 0 0 0)))
       (map nil (lambda (el)
              (when (> el (first top-10))
            (pop top-10)
            (push el top-10)
            (sort top-10 #'<)))
        '( 12 50954 039 09 4 98 34 88 437  728 73 3 7 37 3 8373827 34 328 1 3  23 3 323 23 3545))
       top-10))
Evaluation took:
  0.000 seconds of real time
  0.000047 seconds of total run time (0.000041 user, 0.000006 system)
  100.00% CPU
  127,121 processor cycles
  0 bytes consed

(73 88 98 323 328 437 728 3545 50954 8373827)

CL-USER> (time (let ((top-10 '(0 0 0 0 0 0 0 0 0 0)))
       (map nil (lambda (el)
              (when (> el (first top-10))
            (pop top-10)
            (setf top-10 (merge 'list (list el) top-10 #'<))))
        '(12 50954 039 09 4 98 34 88 437 728 73 3 7 37 3 8373827 34 328 1 3 23 3 323 23 3545))
       top-10))
Evaluation took:
  0.000 seconds of real time
  0.000024 seconds of total run time (0.000021 user, 0.000003 system)
  100.00% CPU
  59,641 processor cycles
  0 bytes consed

(73 88 98 323 328 437 728 3545 50954 8373827)

CL-USER> (time (let ((top-10 '(0 0 0 0 0 0 0 0 0 0)))
       (map nil (lambda (el)
              (when (> el (first top-10))
            (setf (first top-10) el)
            (sort top-10 #'<)))
        '(12 50954 039 09 4 98 34 88 437 728 73 3 7 37 3 8373827 34 328 1 3 23 3 323 23 3545))
       top-10))
Evaluation took:
  0.000 seconds of real time
  0.000036 seconds of total run time (0.000031 user, 0.000005 system)
  100.00% CPU
  95,138 processor cycles
  0 bytes consed

(73 88 98 323 328 437 728 3545 50954 8373827)