Towers of hanoi, problem with running

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

typedef struct { int *x, n; } tower;
tower *new_tower(int cap)
{
    tower *t = calloc(1, sizeof(tower) + sizeof(int) * cap);
    t->x = (int*)(t + 1);
    return t;
}

tower *t[3];
int height;

void text(int y, int i, int d, const char *s)
{
    printf("\033[%d;%dH", height - y + 1, (height + 1) * (2 * i + 1) - d);
    while (d--) printf("%s", s);
}

void add_disk(int i, int d)
{
    t[i]->x[t[i]->n++] = d;
    text(t[i]->n, i, d, "==");

    usleep(100000);
    fflush(stdout);
}

int remove_disk(int i)
{
    int d = t[i]->x[--t[i]->n];
    text(t[i]->n + 1, i, d, "  ");
    return d;
}

void move(int n, int from, int to, int via)
{
    if (!n) return;

    move(n - 1, from, via, to);
    add_disk(to, remove_disk(from));
    move(n - 1, via, to, from);
}

int main(int c, char *v[])
{
    puts("\033[H\033[J");

    if (c <= 1 || (height = atoi(v[1])) <= 0)
        height = 8;
    for (c = 0; c < 3; c++)  t[c] = new_tower(height);
    for (c = height; c; c--) add_disk(0, c);

    move(height, 0, 2, 1);

    text(1, 0, 1, "\n");
    return 0;
}