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int in[] = {10, 32, -1, 567, 3, 18, 1, -51, 789, 0};
main() {
int i;
sort(in, (sizeof in)/(sizeof in[0]));
for (i = 0; i < (sizeof in)/(sizeof in[0]); i++) {
putd(in[i]);
putchar('\n');
}
return 0;
}
/* putd - output decimal number */
putd(n) {
if (n < 0) {
putchar('-');
n = -n;
}
if (n/10)
putd(n/10);
putchar(n%10 + '0');
}
int *xx;
/* sort - sort a[0..n-1] into increasing order */
sort(a, n) int a[]; {
quick(xx = a, 0, --n);
}
/* quick - quicksort a[lb..ub] */
quick(a, lb, ub) int a[]; {
int k, partition();
if (lb >= ub)
return;
k = partition(a, lb, ub);
quick(a, lb, k - 1);
quick(a, k + 1, ub);
}
/* partition - partition a[i..j] */
int partition(a, i, j) int a[]; {
int v, k;
j++;
k = i;
v = a[k];
while (i < j) {
i++; while (a[i] < v) i++;
j--; while (a[j] > v) j--;
if (i < j) exchange(&a[i], &a[j]);
}
exchange(&a[k], &a[j]);
return j;
}
/* exchange - exchange *x and *y */
exchange(x, y) int *x, *y; {
int t;
printf("exchange(%d,%d)\n", x - xx, y - xx);
t = *x; *x = *y; *y = t;
}
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