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; }