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#ifndef lint |
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static const char RCSid[] = "$Id: cnt.c,v 1.5 2022/04/20 20:56:01 greg Exp $"; |
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#endif |
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/* |
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* cnt.c - simple counting program. |
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* |
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* 2/1/88 |
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* |
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* Added -s (shuffle) option April 2022 |
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*/ |
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|
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#include <stdio.h> |
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#include <time.h> |
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#include "random.h" |
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|
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#ifndef uint16 |
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#define uint16 unsigned short /* 16-bit unsigned integer */ |
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#endif |
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#undef uby8 |
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#define uby8 unsigned char /* 8-bit unsigned integer */ |
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|
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#define MAXDIM 50 |
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|
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#define NLEVELS 9 /* number of tree levels */ |
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#define BRORDER 6 /* branches/level */ |
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|
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/* Tree branch structure for quick occupancy search */ |
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/* with 9 levels & 6 branches per level, we can store 1.94 Gbits in 259 MBytes (4.5% overhead) */ |
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const struct { |
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long capacity; /* slots/branch this level */ |
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long skip_bytes; /* bytes until next branch */ |
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int cntr_siz; /* occupancy counter size */ |
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} tree_br[NLEVELS] = { |
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{248L, 32L, 1}, |
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{248L*6, 32L*6+2, 2}, |
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{248L*6*6, (32L*6+2)*6+2, 2}, |
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{248L*6*6*6, ((32L*6+2)*6+2)*6+2, 2}, |
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{248L*6*6*6*6, (((32L*6+2)*6+2)*6+2)*6+3, 3}, |
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{248L*6*6*6*6*6, ((((32L*6+2)*6+2)*6+2)*6+3)*6+3, 3}, |
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{248L*6*6*6*6*6*6, (((((32L*6+2)*6+2)*6+2)*6+3)*6+3)*6+3, 3}, |
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{248L*6*6*6*6*6*6*6, ((((((32L*6+2)*6+2)*6+2)*6+3)*6+3)*6+3)*6+4, 4}, |
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{248L*6*6*6*6*6*6*6*6, (((((((32L*6+2)*6+2)*6+2)*6+3)*6+3)*6+3)*6+4)*6+4, 4}, |
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}; |
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|
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char buf[256]; /* buffer for ordered array output */ |
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|
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|
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/* Encode integer in string and return pointer to end */ |
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static char * |
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tack(char *b, long i) |
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{ |
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char *cp; |
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char *res; |
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|
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*b++ = '\t'; |
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cp = b; |
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if (i == 0) |
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*cp++ = '0'; |
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else |
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do { |
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*cp++ = i%10L + '0'; |
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i /= 10L; |
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} while (i); |
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res = cp--; |
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#define c i |
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while (cp > b) { /* reverse string */ |
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c = *cp; |
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*cp-- = *b; |
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*b++ = c; |
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} |
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#undef c |
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return(res); |
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} |
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|
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|
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/* Loop over dimensions, spitting out buffer after each increment */ |
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static void |
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loop(long *n, char *b) |
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{ |
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long i; |
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|
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if (n[0] == 0) { |
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*b = '\0'; |
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puts(buf); |
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return; |
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} |
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for (i = 0; i < n[0]; i++) |
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loop(n+1, tack(b, i)); |
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} |
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|
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|
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/* Print out shuffled value */ |
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static void |
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print_shuf(long *n, long aval) |
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{ |
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int i; |
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|
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for (i = 0; n[i+1]; i++) { |
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printf("\t%ld", aval % n[i]); |
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aval /= n[i]; |
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} |
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printf("\t%ld\n", aval); |
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} |
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|
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|
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/* Allocate and prepare occupancy tree */ |
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static uby8 * |
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tree_alloc(long alen) |
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{ |
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uby8 *troot; |
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double bytes_per_bit; |
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int i; |
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int ht = 0; |
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/* how tall does our tree need to be? */ |
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while (tree_br[ht].capacity*BRORDER < alen) |
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if (++ht >= NLEVELS) { |
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fputs("Array too large to shuffle\n", stderr); |
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exit(1); |
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} |
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bytes_per_bit = 1.; /* figure out tree size (with overhead) */ |
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for (i = ht; i >= 0; i--) |
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bytes_per_bit += (double)tree_br[i].cntr_siz; |
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bytes_per_bit += (double)tree_br[ht].skip_bytes; |
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bytes_per_bit /= (double)tree_br[ht].capacity; |
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troot = (uby8 *)calloc((long)(alen*bytes_per_bit)+2, 1); |
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if (troot == NULL) { |
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fputs("Not enough memory for shuffle\n", stderr); |
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exit(1); |
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} |
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*troot = ht; /* first byte is tree height */ |
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for (i = 256; i--; ) { /* assign 0-bit count table */ |
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int b; |
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buf[i] = 8; |
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for (b = i; b; b >>= 1) |
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buf[i] -= b&1; |
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} |
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return(troot); |
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} |
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|
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|
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/* Get number of slots available at this branch location */ |
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static long |
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get_avail(const uby8 *ctrp, int lvl) |
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{ |
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long cnt = 0; |
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int n = tree_br[lvl].cntr_siz; |
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|
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while (--n > 0) { /* LSB first */ |
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cnt |= ctrp[n]; |
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cnt <<= 8; |
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} |
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cnt |= ctrp[0]; |
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|
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return(tree_br[lvl].capacity - cnt); |
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} |
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|
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|
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/* Increment branch occupancy counter */ |
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static void |
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incr_counter(uby8 *ctrp, int n) |
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{ |
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n = tree_br[n].cntr_siz; |
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|
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while (n-- > 0) /* LSB first */ |
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if (++(*ctrp++)) |
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break; |
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} |
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|
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|
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/* Skip to and allocate a leaf from tree */ |
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static long |
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eat_nth_leaf(uby8 *brp, long ski) |
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{ |
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int lvl = *brp++; /* tree height in first byte */ |
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long pos = 0; |
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int b; |
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|
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while (lvl >= 0) { /* descend to leaves */ |
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long navail; |
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b = 0; /* select each branch */ |
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while (ski >= (navail = get_avail(brp, lvl))) { |
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if (++b >= BRORDER) { |
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fputs("Shuffle tree error!\n", stderr); |
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exit(1); |
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} |
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pos += tree_br[lvl].capacity; |
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ski -= navail; |
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brp += tree_br[lvl].skip_bytes; |
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} |
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incr_counter(brp, lvl); /* we intend to eat one */ |
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brp += tree_br[lvl--].cntr_siz; /* drop a level */ |
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} |
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while (ski >= buf[*brp]) { /* browse the leaves */ |
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pos += 8; |
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ski -= buf[*brp++]; /* buf contains 0-bit counts */ |
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} |
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b = 0; /* find target bit in byte */ |
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while ((ski -= !(*brp & 1<<b)) >= 0) { |
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pos++; |
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b++; |
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} |
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*brp |= 1<<b; /* eat it */ |
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return(pos); /* & return leaf's slot# */ |
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} |
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|
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|
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/* Shuffle all possible output strings and spit out randomly (tree version) */ |
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static void |
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big_shuffle(long *n, long alen) |
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{ |
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uby8 *tree_root; |
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/* size and allocate holder tree */ |
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tree_root = tree_alloc(alen); |
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|
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while (alen > 0) /* allocate and print random array entries */ |
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print_shuf(n, eat_nth_leaf(tree_root, irandom(alen--))); |
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|
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free(tree_root); /* all done */ |
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} |
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|
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|
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/* Shuffle all possible output strings and spit out randomly */ |
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static void |
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shuffle(long *n) |
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{ |
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long alen; |
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uint16 *myshuf; |
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int i; |
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|
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alen = 1; /* compute shuffle size */ |
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for (i = 0; n[i]; i++) { |
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if (alen*n[i] <= alen) { |
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fputs("Array too large to count!\n", stderr); |
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exit(1); |
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} |
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alen *= n[i]; |
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} |
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/* get unique starting point */ |
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srandom((long)time(0)); |
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|
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if (alen > 1L<<16) { /* use large shuffle method? */ |
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big_shuffle(n, alen); |
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return; |
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} |
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myshuf = (uint16 *)malloc(alen*sizeof(uint16)); |
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if (myshuf == NULL) { |
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fputs("Insufficient memory for shuffle\n", stderr); |
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exit(1); |
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} |
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for (i = alen; i--; ) /* initialize in any order */ |
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myshuf[i] = i; |
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/* perform Fisher-Yates shuffle */ |
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for (i = 0; i < alen-1; i++) { |
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int ix = irandom(alen-i) + i; |
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int ndx = myshuf[i]; |
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myshuf[i] = myshuf[ix]; |
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myshuf[ix] = ndx; |
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} |
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/* put randomly indexed output */ |
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for (i = alen; i--; ) |
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print_shuf(n, (long)myshuf[i]); |
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|
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free(myshuf); /* all done */ |
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} |
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|
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|
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int |
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main(int argc, char *argv[]) |
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{ |
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char *prog = argv[0]; |
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int doshuffle = 0; |
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long n[MAXDIM]; |
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int a; |
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|
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argv++; argc--; |
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if (argc <= 0) |
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goto userr; |
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if (argv[0][0] == '-' && argv[0][1] == 's') { |
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doshuffle = 1; |
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argv++; argc--; |
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} |
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for (a = 0; a < argc; a++) |
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if ((n[a] = atol(argv[a])) <= 1) |
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goto userr; |
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n[a] = 0; |
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if (!a) |
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goto userr; |
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|
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if (doshuffle) |
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shuffle(n); |
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else |
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loop(n, buf); |
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|
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return(0); |
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userr: |
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fputs("Usage: ", stderr); |
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fputs(prog, stderr); |
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fputs(" [-s] N0 [N1 ..]\n", stderr); |
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return(1); |
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} |
