update

Task/Sorting-algorithms-Shell-sort/C++/sorting-algorithms-shell-sort.cpp

@@ -0,0 +1,73 @@
+#include <time.h>
+#include <iostream>
+
+//--------------------------------------------------------------------------------------------------
+using namespace std;
+
+//--------------------------------------------------------------------------------------------------
+const int MAX = 126;
+class shell
+{
+public:
+    shell()
+    { _gap[0] = 1750; _gap[1] = 701; _gap[2] = 301; _gap[3] = 132; _gap[4] = 57; _gap[5] = 23; _gap[6] = 10; _gap[7] = 4; _gap[8] = 1; }
+
+    void sort( int* a, int count )
+    {
+	_cnt = count;
+	for( int x = 0; x < 9; x++ )
+	    if( count > _gap[x] )
+	    { _idx = x; break; }
+
+	sortIt( a );
+    }
+
+private:	
+    void sortIt( int* arr )
+    {
+	bool sorted = false;
+	while( true )
+	{
+	    sorted = true;
+	    int st = 0;
+	    for( int x = _gap[_idx]; x < _cnt; x += _gap[_idx] )
+	    {
+		if( arr[st] > arr[x] )
+		{ swap( arr[st], arr[x] ); sorted = false; }
+		st = x;
+	    }
+	    if( ++_idx >= 8 ) _idx = 8;
+	    if( sorted && _idx == 8 ) break;
+	}
+    }
+
+    void swap( int& a, int& b ) { int t = a; a = b; b = t; }
+
+    int _gap[9], _idx, _cnt;
+};
+//--------------------------------------------------------------------------------------------------
+int main( int argc, char* argv[] )
+{
+    srand( static_cast<unsigned int>( time( NULL ) ) ); int arr[MAX];
+    for( int x = 0; x < MAX; x++ )
+	arr[x] = rand() % MAX - rand() % MAX;
+
+    cout << " Before: \n=========\n";
+    for( int x = 0; x < 7; x++ )
+    {
+	for( int a = 0; a < 18; a++ )
+	{ cout << arr[x * 18 + a] << " "; }
+	cout << endl;
+    }
+    cout << endl; shell s; s.sort( arr, MAX );
+	
+    cout << " After: \n========\n";
+    for( int x = 0; x < 7; x++ )
+    {
+	for( int a = 0; a < 18; a++ )
+	{ cout << arr[x * 18 + a] << " "; }
+	cout << endl;
+    }
+    cout << endl << endl; return system( "pause" );
+}
+//--------------------------------------------------------------------------------------------------

Task/Sorting-algorithms-Shell-sort/Racket/sorting-algorithms-shell-sort.rkt

@@ -0,0 +1,14 @@
+#lang racket
+(define (shell-sort! xs)
+  (define (ref i) (vector-ref xs i))
+  (define (new Δ) (if (= Δ 2) 1 (exact-floor (/ (* Δ 5) 11))))
+  (let loop ([Δ (quotient (vector-length xs) 2)])
+    (unless (= Δ 0)
+      (for ([xi (in-vector xs)] [i (in-naturals)])
+        (let while ([i i])
+          (cond [(and (>= i Δ) (> (ref (- i Δ)) xi))
+                 (vector-set! xs i (ref (- i Δ)))
+                 (while (- i Δ))]
+                [(vector-set! xs i xi)])))
+      (loop (new Δ))))
+  xs)