程序所需的标准头文件:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
主程序从这里开始:
const char *tgt[]={"bacon", "Bacon", "mIlk",
"Milk", "spinach", "MILK", "milk", "eggs"};
int tgt_size=8;
int SortLookupTable[128];
typedef int cmp_t (const void *, const void *);
int main(int argc, char *argv[]) {
printf("Before sort:\n\n");
int n=0;
for(n=0; n<tgt_size; n++)
printf("%s\n", tgt[n]);
CreateSortTable();
myQsort(tgt, tgt_size, sizeof(char *), &compare);
printf("\n\n====\n\n");
for(n=0; n<tgt_size; n++)
printf("%s\n", tgt[n]);
return 0;
}
根据需求定制排序表格:
void CreateSortTable(void){
int i;
for (i = 0; i < 128; i++){
SortLookupTable[i] = 0;
}
char *s;
s=(char *)malloc(64);
memset(s, 0, 64);
strcpy(s, "aAbBcCdDeEfFgGhHiIjJkKlLmMnNoOpPqQrRsStTuUvVwWxXyYzZ");
i=1;
for (; *s; s++){
SortLookupTable[(int) ((unsigned char) *s)]=i;
i++;
}
}
快速排序算法,您也可以使用标准库提供的方法:
=======
#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
#define swap(a, b) \
if (swaptype == 0) { \
long t = *(long *)(a); \
*(long *)(a) = *(long *)(b); \
*(long *)(b) = t; \
} else \
swapfunc(a, b, es, swaptype)
#define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
#define swapcode(TYPE, parmi, parmj, n) { \
long i = (n) / sizeof (TYPE); \
register TYPE *pi = (TYPE *) (parmi); \
register TYPE *pj = (TYPE *) (parmj); \
do { \
register TYPE t = *pi; \
*pi++ = *pj; \
*pj++ = t; \
} while (--i > 0); \
}
#define min(a, b) (a) < (b) ? a : b
void swapfunc(char *a, char *b, int n, int swaptype){
if(swaptype <= 1)
swapcode(long, a, b, n)
else
swapcode(char, a, b, n)
}
char * med3(char *a, char *b, char *c, cmp_t *cmp){
if ( cmp(a, b) < 0){
if (cmp(b, c) < 0){
return b;
}else{
if ( cmp(a, c) < 0){
return c;
}else{
return a;
}
}
}else{
if (cmp(b, c) < 0){
return b;
}else{
if ( cmp(a, c) < 0){
return a;
}else{
return c;
}
}
}
}
void myQsort(void *a, unsigned int n, unsigned int es, cmp_t *cmp){
char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
int d, r, swaptype, swap_cnt;
loop: SWAPINIT(a, es);
swap_cnt = 0;
if (n < 7) {
for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
for (pl = pm; pl > (char *)a && cmp(pl - es, pl) > 0; pl -= es){
swap(pl, pl - es);
}
return;
}
pm = (char *)a + (n / 2) * es;
if (n > 7) {
pl = a;
pn = (char *)a + (n - 1) * es;
if (n > 40) {
d = (n / 8) * es;
pl = med3(pl, pl + d, pl + 2 * d, cmp);
pm = med3(pm - d, pm, pm + d, cmp);
pn = med3(pn - 2 * d, pn - d, pn, cmp);
}
pm = med3(pl, pm, pn, cmp);
}
swap(a, pm);
pa = pb = (char *)a + es;
pc = pd = (char *)a + (n - 1) * es;
for (;;) {
while (pb <= pc && (r = cmp(pb, a)) <= 0) {
if (r == 0) {
swap_cnt = 1;
swap(pa, pb);
pa += es;
}
pb += es;
}
while (pb <= pc && (r = cmp(pc, a)) >= 0) {
if (r == 0) {
swap_cnt = 1;
swap(pc, pd);
pd -= es;
}
pc -= es;
}
if (pb > pc)
break;
swap(pb, pc);
swap_cnt = 1;
pb += es;
pc -= es;
}
if (swap_cnt == 0) {
for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
for (pl = pm; pl > (char *)a && cmp(pl - es, pl) > 0;
pl -= es)
swap(pl, pl - es);
return;
}
pn = (char *)a + n * es;
r = min(pa - (char *)a, pb - pa);
vecswap(a, pb - r, r);
r = min(pd - pc, pn - pd - es);
vecswap(pb, pn - r, r);
if ((r = pb - pa) > es)
myQsort(a, r / es, es, cmp);
if ((r = pd - pc) > es) {
a = pn - r;
n = r / es;
goto loop;
}
}
两个最重要的功能是:
unsigned char Change(char a){
return (unsigned char ) SortLookupTable[(int)a];
}
int compare (const void *a, const void *b){
char *s1= *(char **)a;
char *s2= *(char **)b;
int ret, len, i;
ret=0;
if (strlen((void*)s1) > strlen((void*)s2)){
len=strlen((void*)s1);
}else{
len=strlen((void*)s2) ;
}
for(i=0; i<len; i++){
if ( s1[i] != s2[i]){
if ( Change(s1[i]) < Change(s2[i]) ){
ret=0;
break;
}else{
ret=1;
break;
}
}
}
return ret;
}