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

#include "llist.h"
#include "stack.h"


void current_status(stack *S)
{
    int i;
    printf("------\n");
    for (i = 0; i < 3; i++) { 
	print_stack(S + i);
	if (!check_order(S + i)) {
	    printf("INVALID STACK\n");
	    exit(1);
	}
    }
    return;
}


int main(int argc, char **argv)
{
    int i, n, from, to;
    stack S[3];
    FILE *in;
    if (argc < 2) {
    	printf("Usage: %s <n> [ filename ]\n", argv[0]);
    	exit(1);
    }
    n = atoi(argv[1]);
    // for (i = 0; i < 3; i++) init_stack(&S[i]);
    for (i = 0; i < 3; i++) init_stack(S + i);
    for (i = n; i > 0; i--) push(&S[0], i);
    current_status(S);
    
    if (argc == 3) { 
	in = fopen(argv[2], "r");
	if (in == NULL) {
	    printf("Failed to open %s\n", argv[2]);
	    exit(1);
	}
    }
    else in = stdin;
    /* while (!feof(in)) { */
    while (fscanf(in, "%d%d", &from, &to) == 2) {
	/* printf("%d -> %d\n", from, to); */
	push(S + to - 1, pop(S + from - 1));
	current_status(S);
    }
    /* } */
    return 0;
}