uva 101 the blocks problem

uva老不让过……
注意：

• move a onto b

where a and b areblock numbers, puts block a onto block b afterreturning any blocks that are stacked on top of blocks a and b to their initial positions.

to their initial positions.是指一开始的位置，即4号石块回到第4号栈。

Any command in which a = b orin which a and b are in the same stack ofblocks is an illegal command. All illegal commands should be ignored and shouldhave no affect on the configuration of blocks.

这个千万要小心，一不留神会造成程序runtime error，这种非法情况直接忽略。不忽略的话，小心堆成一个很高很高的栈……

效率情况：

Total Submissions	Users that tried it	Users that solved it
65347	13675	8497

Your best accepted try
Ranking	Submission	Run Time	Language	Submission Date
490	9624560	0.008	C++	2012-01-07 05:20:01

读题相当重要，比刷牙还重要。不把题目读得精透，千万不要急着下手……

#include<stdio.h>
const int maxn=30;

int s[maxn][maxn],top[maxn],pos[maxn],t[maxn],t_top,n;

void init()
{
	for(int i=0;i<n;i++)
	{
		s[i][1]=i;
		top[i]=1;
		pos[i]=i;
	}
}

void move(int p,int x)
{
	while(s[p][top[p]]!=x)
	{
		int a=s[p][top[p]--];
		s[a][++top[a]]=a;
		pos[a]=a;
	}
}

void print_ans()
{
	for(int i=0;i<n;i++)
	{
		printf("%d:",i);
		for(int j=1;j<=top[i];j++)
		  printf(" %d",s[i][j]);
  		printf("\n");
	}
}

int main()
{
#ifndef ONLINE_JUDGE
	freopen("101.txt","r",stdin);
#endif
	scanf("%d",&n);
	init();
	char s1[5],s2[5];
	int a,b;
	while(scanf("%s%d%s%d",s1,&a,s2,&b)==4)
	{
		if(a==b || pos[a]==pos[b]) continue;
		if(s1[0]=='m')
		{
			move(pos[a],a);
			top[pos[a]]--;
			pos[a]=pos[b];
			if(s2[1]=='n')
			{
				move(pos[b],b);
				s[pos[b]][++top[pos[b]]]=a;
			}
			else s[pos[b]][++top[pos[b]]]=a;
		}
		else
		{
			t_top=0;
			while(1)
			{
				t[++t_top]=s[pos[a]][top[pos[a]]--];
				pos[t[t_top]]=pos[b];
				if(t[t_top]==a) break;
			}
			if(s2[1]=='n')
				move(pos[b],b);
			while(t_top)
				s[pos[b]][++top[pos[b]]]=t[t_top--];
		}
		//printf("%s %d %s %d\n",s1,a,s2,b);
		//print_ans();
	}
	print_ans();
	return 0;
}