Data update

Task/Sorting-algorithms-Quicksort/XBasic/sorting-algorithms-quicksort.basic

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+' Sorting algorithms/Quicksort
+PROGRAM "quicksort"
+VERSION "1.0"
+
+IMPORT "xst"
+
+DECLARE FUNCTION Entry ()
+DECLARE FUNCTION QuickSort (@arr%[], l%%, r%%)
+' Pseudo-random number generator
+' Based on the rand, srand functions from Kernighan & Ritchie's book
+' 'The C Programming Language'
+DECLARE FUNCTION Rand()
+DECLARE FUNCTION SRand(seed%%)
+
+FUNCTION Entry ()
+  DIM arr%[19]
+  a%% = 0
+  b%% = UBOUND(arr%[])
+  XstGetSystemTime (@msec)
+  SRand(INT(msec) MOD 32768)
+  FOR i%% = a%% TO b%%
+    arr%[i%%] = INT(Rand() / 32768.0 * 99.0)
+  NEXT i%%
+  PRINT "Unsorted:"
+  FOR i%% = a%% TO b%%
+    PRINT FORMAT$("## ", arr%[i%%]);
+  NEXT i%%
+  PRINT
+  PRINT "Sorted:"
+  QuickSort(@arr%[], a%%, b%%)
+  FOR i%% = a%% TO b%%
+    PRINT FORMAT$("## ", arr%[i%%]);
+  NEXT i%%
+  PRINT
+END FUNCTION
+
+FUNCTION QuickSort (@arr%[], l%%, r%%)
+  leftIndex%% = l%%
+  rightIndex%% = r%%
+  IF r%% > l%% THEN
+    pivot%% = (l%% + r%%) \ 2
+    DO WHILE (leftIndex%% <= pivot%%) AND (rightIndex%% >= pivot%%)
+      DO WHILE (arr%[leftIndex%%] < arr%[pivot%%]) AND (leftIndex%% <= pivot%%)
+        INC leftIndex%%
+      LOOP
+      DO WHILE (arr%[rightIndex%%] > arr%[pivot%%]) AND (rightIndex%% >= pivot%%)
+        DEC rightIndex%%
+      LOOP
+      SWAP arr%[leftIndex%%], arr%[rightIndex%%]
+      INC leftIndex%%
+      DEC rightIndex%%
+      SELECT CASE TRUE
+        CASE leftIndex%% - 1 = pivot%%:
+          INC rightIndex%%
+          pivot%% = rightIndex%%
+        CASE rightIndex%% + 1 = pivot%%:
+          DEC leftIndex%%
+          pivot%% = leftIndex%%
+      END SELECT
+    LOOP
+    QuickSort (@arr%[], l%%, pivot%% - 1)
+    QuickSort (@arr%[], pivot%% + 1, r%%)
+  END IF
+END FUNCTION
+
+' Return pseudo-random integer on 0..32767
+FUNCTION Rand()
+  #next&& = #next&& * 1103515245 + 12345
+END FUNCTION USHORT(#next&& / 65536) MOD 32768
+
+' Set seed for Rand()
+FUNCTION SRand(seed%%)
+  #next&& = seed%%
+END FUNCTION
+END PROGRAM