例题5-2 木块问题（The Blocks Problem，UVa 101）

原题链接：https://vjudge.net/problem/UVA-101
分类：<vector>
备注：vector的使用
注意：要优先查询a,b的位置，如果在同一个堆则指令非法，找下一个指令。

代码如下：

#include<cstdio>
#include<string>
#include<vector>
#include<iostream>
using namespace std;
int n, a, b, pa, ha, pb, hb;
vector<int>block[30];
string cmd1, cmd2;
void find_pos(int& p, int& h, int x)
{
	for (p = 0; p < n; p++)
		for (h = 0; h < block[p].size(); h++)
			if (block[p][h] == x)
				return;
}
void ret(int p, int h)
{
	for (int i = h + 1; i < block[p].size(); i++)
		block[block[p][i]].push_back(block[p][i]);
	block[p].resize(h + 1);
}
void put_up()
{
	for (int i = ha; i < block[pa].size(); i++)
		block[pb].push_back(block[pa][i]);
	block[pa].resize(ha);
}
int main(void)
{
	scanf("%d", &n);
	for (int i = 0; i < n; i++)
		block[i].push_back(i);
	while (cin >> cmd1)
	{
		if (cmd1 == "quit")break;
		cin >> a >> cmd2 >> b;
		find_pos(pa, ha, a), find_pos(pb, hb, b);
		if (pa == pb)continue;
		if (cmd1 == "move")ret(pa, ha);
		if (cmd2 == "onto")ret(pb, hb);
		put_up();
	}
	for (int i = 0; i < n; i++)
	{
		printf("%d:", i);
		for (int j = 0; j < block[i].size(); j++)
			printf(" %d", block[i][j]);
		printf("\n");
	}
	return 0;
}