fix qsort
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2901f98fce
commit
80956130b8
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@ -19,69 +19,60 @@
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* along with GNU Mes. If not, see <http://www.gnu.org/licenses/>.
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* along with GNU Mes. If not, see <http://www.gnu.org/licenses/>.
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*/
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*/
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#include <assert.h>
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#include <stdlib.h>
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#include <stdlib.h>
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#include <string.h>
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#if 1
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static void
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static void
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qswap (char *a, char *b, size_t size)
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qswap (char *a, char *b, size_t size)
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{
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{
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while (size-- > 0);
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while (size-- > 0)
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{
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{
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char tmp = *a;
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char tmp = *a;
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*a++ = *b;
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*a++ = *b;
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*b++ = tmp;
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*b++ = tmp;
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}
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}
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}
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}
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#else
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static void
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qswap (void *a, void *b, int size)
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{
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assert (a != b);
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char buffer[size];
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memcpy (buffer, a, size);
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memcpy (a, b, size);
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memcpy (b, buffer, size);
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}
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#endif
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static size_t
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static int
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qpart (char *base, size_t count, size_t size,
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qpart (char *base, int lo, int hi, size_t size,
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int (*compare) (void const *, void const *))
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int (*compare) (void const *, void const *))
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{
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{
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void *p1 = base + count * size;
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char *pivot = base + hi * size;
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size_t i = 0;
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int i = lo - 1;
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for (size_t j = 0; j < count; j++)
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for (int j = lo; j < hi; j++)
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{
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{
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char *p2 = base + j * size;
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char *pj = base + j * size;
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int c = p1 == p2 ? 0 : compare (p2, p1);
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if (pj != pivot && compare (pj, pivot) < 0)
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if (c == 0)
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i++;
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else if (c < 0)
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{
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{
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char *p1 = base + i * size;
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qswap (p1, p2, size);
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i++;
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i++;
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void *pi = base + i * size;
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qswap (pi, pj, size);
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}
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}
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}
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}
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char *p2 = base + i * size;
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i++;
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if (p1 != p2 && compare (p1, p2) < 0)
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char *pi = base + i * size;
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qswap (p1, p2, size);
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qswap (pi, pivot, size);
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return i;
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return i;
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}
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}
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static void
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_qsort (void *base, int lo, int hi, size_t size,
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int (*compare) (void const *, void const *))
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{
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if (lo >= hi || lo < 0)
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return;
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int pi = qpart (base, lo, hi, size, compare);
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_qsort (base, lo, pi - 1, size, compare);
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_qsort (base, pi + 1, hi, size, compare);
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}
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void
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void
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qsort (void *base, size_t count, size_t size,
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qsort (void *base, size_t count, size_t size,
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int (*compare) (void const *, void const *))
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int (*compare) (void const *, void const *))
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{
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{
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if (count <= 1)
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if (count <= 1)
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return;
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return;
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size_t p = qpart (base, count - 1, size, compare);
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_qsort (base, 0, count - 1, size, compare);
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qsort (base, p, size, compare);
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char *pbase = base;
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char *p1 = pbase + p * size;
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size_t c1 = count - p;
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qsort (p1, c1, size, compare);
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}
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}
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