Subversion Repositories eco32

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;

}