Foundation: Shellsort

/* Shell Sorting. * Implemention history:. * 2013-09-15, Mars Fu, first version. *//* [Shell Sorting Algorithm]. * Published by Donald L. Shell [CACM 2, 7(July 1959), 30-32]. */#include "stdafx.h"#include "shellsort.h"#include <math.h>static int get_increment(int s){int next_hs;next_hs = (1 << s);return next_hs;}intdo_shell_sort(void* src, int src_sz, int n, cmp_func cmp, exc_func exchange, dbg_func dbg){int t;int h;int i,j;float n2;F_S();if (src == NULL || cmp == NULL || exchange == NULL) return 0;if (src_sz <= 0 || n <= 0) return 0;/* get @t for aux table {h(t),...,h(0)}     */n2 = 2;t = log((double)n) / log((double)n2) + (n%2 ? 1 : -1);/* loop aux table for shell sorting  */while (t >= 0) { h = get_increment(t); /* get h(t) *//* loop all parts of @src, each part has @h items to be compared. */for (i = 0; i < n/h; ++i) {/* do the comparison and exchanging for each part. */for ( j = i+h; j < n; j += h) {if (cmp((char*)src + (j-h)*src_sz, (char*)src + j*src_sz) > 0) {exchange((char*)src + (j-h) * src_sz, (char*)src + j * src_sz);}}}    --t;if (dbg != NULL) dbg(src, n, h);}F_E();return 1;}#ifdef SHELL_SORT_DEBUGstatic int int_increasing_cmp(void* lv, void* rv){int tmp_lv, tmp_rv;tmp_lv = *(int*)lv;tmp_rv = *(int*)rv;return (tmp_lv - tmp_rv);}static voidexchange_int_item(void* lv, void* rv){int tmp_lv, tmp_rv;tmp_lv = *(int*)lv;tmp_rv = *(int*)rv;*(int*)lv = *(int*)rv;*(int*)rv = tmp_lv;}static voiddebug_func(void*src, int n, int h){int i;debug("%d-sort:\r\n----\r\n", h);for (i = 0; i < n; ++i) {debug("%d ", *((int*)src + i));}debug("\r\n----\r\n");}intmain(int argc, char* argv[]){int i;int cnt;const int int_items[] = { 503, 87, 512, 61, 908, 170, 897, 275,                       653, 426, 154, 509, 612, 677, 765, 703                         };int ret;debug("[Testing shell sort].. \r\n");cnt = sizeof(int_items)/sizeof(int_items[0]);debug("src database:\r\n----\r\n");for (i = 0; i < cnt; ++i) {debug("%d ", int_items[i]);}debug("\r\n----\r\n");ret = do_shell_sort((void*)int_items, sizeof(int), cnt,                  int_increasing_cmp, exchange_int_item, debug_func);if (!ret) {debug("failed. \r\n");goto END;}debug("dst database:\r\n----\r\n");for (i = 0; i < cnt; ++i) {debug("%d ", int_items[i]);}debug("\r\n----\r\n");debug("\r\n");debug("[Testing shell sort].. done. \r\n");END:while(1);return 0;}#endif /* SHELL_SORT_DEBUG */

#ifndef __SHELLSORT_H__#define __SHELLSORT_H__#define SHELL_SORT_DEBUGtypedef int(*cmp_func)(void*, void*);typedef void (*exc_func)(void*, void*);typedef void (*dbg_func)(void*, int, int);int do_shell_sort(void* src, int src_sz, int n, cmp_func cmp, exc_func exchange, dbg_func dbg);#endif /* __SHELLSORT_H__ */

#pragma once#include <windows.h>#ifdef _WIN32#define msleep(x)  Sleep(x)#endif#include <stdio.h>#include <tchar.h>#include <stdlib.h>#include <malloc.h>#include <string.h>#include <math.h>#define MY_DEBUG#ifdef MY_DEBUG#define debug printf#else#define debug(x,argc, __VA_ARGS__);#endif /* MY_DEBUG */#define F_S() debug("[%s]..\r\n", __FUNCTION__)#define F_E() debug("[%s]..done. \r\n", __FUNCTION__)

Mars

Sep 15th, 2013