用Lisp语言实现快速排序(快排)算法

实现代码如下：

[plain] 
(defun main-qsort (arr) 
  (let ((start 0) (end (- (length arr) 1))) 
    (qsort start end arr)) 
  (print arr) 
) 
 
(defun qsort (start end arr)        ;note the variable arr is a list 
  (when (< end start) 
    (return-from qsort NIL)) 
  (when (= end start) 
    (if (> (elt arr start) (elt arr end))  
    (rotatef (elt arr start) (elt arr end))) 
    (return-from qsort T)) 
  (when (> end start) 
    (let ((mid (partition start end arr))) 
      ;(format t "mid=~d  (~d, ~d)" mid start end) (print arr) 
      (when (or (< mid start) (> mid end)) 
    (return-from qsort NIL)) 
      (when (and (= mid start) (qsort (+ mid 1) end arr)) 
    (return-from qsort T)) 
      (when (and (= mid end) (qsort start (- mid 1) arr)) 
    (return-from qsort T)) 
      (when (and (> mid start) (< mid end)  
         (qsort start (- mid 1) arr) 
         (qsort (+ mid 1) end arr)) 
    (return-from qsort T)) 
      )) 
) 
 
(defun partition (start end arr)    ;note the variable arr is a list 
  (let ((i (- start 1))) 
    (do ((j start (1+ j))) 
    ((= end j) (1+ i)) 
      (when (< (elt arr j) (elt arr end)) 
    (incf i) 
    (+ j end) 
    (rotatef (elt arr i) (elt arr j)) 
    )) 
    (rotatef (elt arr (1+ i)) (elt arr end)) 
    ;(print arr) 
    (+ (1+ i))) 
) 

(defun main-qsort (arr)
  (let ((start 0) (end (- (length arr) 1)))
    (qsort start end arr))
  (print arr)
)

(defun qsort (start end arr)  ;note the variable arr is a list
  (when (< end start)
    (return-from qsort NIL))
  (when (= end start)
    (if (> (elt arr start) (elt arr end))
 (rotatef (elt arr start) (elt arr end)))
    (return-from qsort T))
  (when (> end start)
    (let ((mid (partition start end arr)))
      ;(format t "mid=~d  (~d, ~d)" mid start end) (print arr)
      (when (or (< mid start) (> mid end))
 (return-from qsort NIL))
      (when (and (= mid start) (qsort (+ mid 1) end arr))
 (return-from qsort T))
      (when (and (= mid end) (qsort start (- mid 1) arr))
 (return-from qsort T))
      (when (and (> mid start) (< mid end)
   (qsort start (- mid 1) arr)
   (qsort (+ mid 1) end arr))
 (return-from qsort T))
      ))
)

(defun partition (start end arr) ;note the variable arr is a list
  (let ((i (- start 1)))
    (do ((j start (1+ j)))
 ((= end j) (1+ i))
      (when (< (elt arr j) (elt arr end))
 (incf i)
  (+ j end)
 (rotatef (elt arr i) (elt arr j))
 ))
    (rotatef (elt arr (1+ i)) (elt arr end))
    ;(print arr)
    (+ (1+ i)))
  

补充：综合编程 , 其他综合 ,

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