The Quake III Arena sources as originally released under the GPL license on August 20, 2005.

lcc/tst/sort.c

@@ -0,0 +1,65 @@
+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;
+}