Added multikey quicksort

This commit is contained in:
Jian 2019-10-03 17:04:48 +10:00
parent 8963e54237
commit ffebcd5fdb
1 changed files with 407 additions and 0 deletions

View File

@ -0,0 +1,407 @@
/* demo.c -- Implementations of multikey quicksort and ternary search trees
Usage
demo Run basic timings on /usr/dict/words
demo <file> Run basic timings on <file>
demo <file> trysearch Interactive pm and nn search on <file>
demo <file> nncost Run near neigbhor expers on <file>
demo <file> pmcost Interactive partial match expers on <file>
*/
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <time.h>
// MULTIKEY QUICKSORT
#ifndef min
#define min(a, b) ((a) <= (b) ? (a) : (b))
#endif
#define swap(a, b) \
{ \
char *t = x[a]; \
x[a] = x[b]; \
x[b] = t; \
}
#define i2c(i) x[i][depth]
void vecswap(int i, int j, int n, char *x[])
{
while (n-- > 0)
{
swap(i, j);
i++;
j++;
}
}
void ssort1(char *x[], int n, int depth)
{
int a, b, c, d, r, v;
if (n <= 1)
return;
a = rand() % n;
swap(0, a);
v = i2c(0);
a = b = 1;
c = d = n - 1;
for (;;)
{
while (b <= c && (r = i2c(b) - v) <= 0)
{
if (r == 0)
{
swap(a, b);
a++;
}
b++;
}
while (b <= c && (r = i2c(c) - v) >= 0)
{
if (r == 0)
{
swap(c, d);
d--;
}
c--;
}
if (b > c)
break;
swap(b, c);
b++;
c--;
}
r = min(a, b - a);
vecswap(0, b - r, r, x);
r = min(d - c, n - d - 1);
vecswap(b, n - r, r, x);
r = b - a;
ssort1(x, r, depth);
if (i2c(r) != 0)
ssort1(x + r, a + n - d - 1, depth + 1);
r = d - c;
ssort1(x + n - r, r, depth);
}
void ssort1main(char *x[], int n)
{
ssort1(x, n, 0);
}
// ssort2 -- Faster Version of Multikey Quicksort
void vecswap2(char **a, char **b, int n)
{
while (n-- > 0)
{
char *t = *a;
*a++ = *b;
*b++ = t;
}
}
#define swap2(a, b) \
{ \
t = *(a); \
*(a) = *(b); \
*(b) = t; \
}
#define ptr2char(i) (*(*(i) + depth))
char **med3func(char **a, char **b, char **c, int depth)
{
int va, vb, vc;
if ((va = ptr2char(a)) == (vb = ptr2char(b)))
return a;
if ((vc = ptr2char(c)) == va || vc == vb)
return c;
return va < vb ? (vb < vc ? b : (va < vc ? c : a))
: (vb > vc ? b : (va < vc ? a : c));
}
#define med3(a, b, c) med3func(a, b, c, depth)
void inssort(char **a, int n, int d)
{
char **pi, **pj, *s, *t;
for (pi = a + 1; --n > 0; pi++)
for (pj = pi; pj > a; pj--)
{
// Inline strcmp: break if *(pj-1) <= *pj
for (s = *(pj - 1) + d, t = *pj + d; *s == *t && *s != 0; s++, t++)
;
if (*s <= *t)
break;
swap2(pj, pj - 1);
}
}
void ssort2(char **a, int n, int depth)
{
int d, r, partval;
char **pa, **pb, **pc, **pd, **pl, **pm, **pn, *t;
if (n < 10)
{
inssort(a, n, depth);
return;
}
pl = a;
pm = a + (n / 2);
pn = a + (n - 1);
if (n > 30)
{ // On big arrays, pseudomedian of 9
d = (n / 8);
pl = med3(pl, pl + d, pl + 2 * d);
pm = med3(pm - d, pm, pm + d);
pn = med3(pn - 2 * d, pn - d, pn);
}
pm = med3(pl, pm, pn);
swap2(a, pm);
partval = ptr2char(a);
pa = pb = a + 1;
pc = pd = a + n - 1;
for (;;)
{
while (pb <= pc && (r = ptr2char(pb) - partval) <= 0)
{
if (r == 0)
{
swap2(pa, pb);
pa++;
}
pb++;
}
while (pb <= pc && (r = ptr2char(pc) - partval) >= 0)
{
if (r == 0)
{
swap2(pc, pd);
pd--;
}
pc--;
}
if (pb > pc)
break;
swap2(pb, pc);
pb++;
pc--;
}
pn = a + n;
r = min(pa - a, pb - pa);
vecswap2(a, pb - r, r);
r = min(pd - pc, pn - pd - 1);
vecswap2(pb, pn - r, r);
if ((r = pb - pa) > 1)
ssort2(a, r, depth);
if (ptr2char(a + r) != 0)
ssort2(a + r, pa - a + pn - pd - 1, depth + 1);
if ((r = pd - pc) > 1)
ssort2(a + n - r, r, depth);
}
void ssort2main(char **a, int n) { ssort2(a, n, 0); }
// TERNARY SEARCH TREE ALGS
typedef struct tnode *Tptr;
typedef struct tnode
{
char splitchar;
Tptr lokid, eqkid, hikid;
} Tnode;
Tptr root;
// Insert 1 -- Simple Insertion Algorithm
Tptr insert1(Tptr p, char *s)
{
if (p == 0)
{
p = (Tptr)malloc(sizeof(Tnode));
p->splitchar = *s;
p->lokid = p->eqkid = p->hikid = 0;
}
if (*s < p->splitchar)
p->lokid = insert1(p->lokid, s);
else if (*s == p->splitchar)
{
if (*s != 0)
p->eqkid = insert1(p->eqkid, ++s);
}
else
p->hikid = insert1(p->hikid, s);
return p;
}
void cleanup1(Tptr p)
{
if (p)
{
cleanup1(p->lokid);
cleanup1(p->eqkid);
cleanup1(p->hikid);
free(p);
}
}
// Insert 2 -- Faster version of Insert
#define BUFSIZE 1000
Tptr buf;
int bufn, freen;
void *freearr[10000];
int storestring = 0;
void insert2(char *s)
{
int d;
char *instr = s;
Tptr pp, *p;
p = &root;
while (pp = *p)
{
if ((d = *s - pp->splitchar) == 0)
{
if (*s++ == 0)
return;
p = &(pp->eqkid);
}
else if (d < 0)
p = &(pp->lokid);
else
p = &(pp->hikid);
}
for (;;)
{
// *p = (Tptr) malloc(sizeof(Tnode));
if (bufn-- == 0)
{
buf = (Tptr)malloc(BUFSIZE *
sizeof(Tnode));
freearr[freen++] = (void *)buf;
bufn = BUFSIZE - 1;
}
*p = buf++;
pp = *p;
pp->splitchar = *s;
pp->lokid = pp->eqkid = pp->hikid = 0;
if (*s++ == 0)
{
if (storestring)
pp->eqkid = (Tptr)instr;
return;
}
p = &(pp->eqkid);
}
}
void cleanup2()
{
int i;
for (i = 0; i < freen; i++)
free(freearr[i]);
}
// Search Algorithms
int search1(char *s)
{
Tptr p;
p = root;
while (p)
{
if (*s < p->splitchar)
p = p->lokid;
else if (*s == p->splitchar)
{
if (*s++ == 0)
return 1;
p = p->eqkid;
}
else
p = p->hikid;
}
return 0;
}
int search2(char *s)
{
int d, sc;
Tptr p;
sc = *s;
p = root;
while (p)
{
if ((d = sc - p->splitchar) == 0)
{
if (sc == 0)
return 1;
sc = *++s;
p = p->eqkid;
}
else if (d < 0)
p = p->lokid;
else
p = p->hikid;
}
return 0;
}
// Advanced searching: Partial match, near words
int nodecnt;
char *srcharr[100000];
int srchtop;
void pmsearch(Tptr p, char *s)
{
if (!p)
return;
nodecnt++;
if (*s == '.' || *s < p->splitchar)
pmsearch(p->lokid, s);
if (*s == '.' || *s == p->splitchar)
if (p->splitchar && *s)
pmsearch(p->eqkid, s + 1);
if (*s == 0 && p->splitchar == 0)
srcharr[srchtop++] =
(char *)p->eqkid;
if (*s == '.' || *s > p->splitchar)
pmsearch(p->hikid, s);
}
void nearsearch(Tptr p, char *s, int d)
{
if (!p || d < 0)
return;
nodecnt++;
if (d > 0 || *s < p->splitchar)
nearsearch(p->lokid, s, d);
if (p->splitchar == 0)
{
if ((int)strlen(s) <= d)
srcharr[srchtop++] =
(char *)p->eqkid;
}
else
nearsearch(p->eqkid, *s ? s + 1 : s,
(*s == p->splitchar) ? d : d - 1);
if (d > 0 || *s > p->splitchar)
nearsearch(p->hikid, s, d);
}
#define NUMBER_OF_STRING 3
int main(int argc, char *argv[])
{
char *arr[NUMBER_OF_STRING] = {"apple", "cat", "boy"};
ssort1main(arr, NUMBER_OF_STRING);
for (int i = 0; i < NUMBER_OF_STRING; i++)
{
printf("%s ", arr[i]);
}
}