Working at the Restaurant
Description
Last night, Tom went on a date with a really nice girl. However, he forgot to take his credit card with him and he had no cash in his wallet, so he ended up working at the restaurant to pay for the bill.
His task is to take plates from the waiter when he comes from the tables, and pass them along when the diswasher requests them. It is very important for the plates to be washed in the same order as they are brought from the tables, as otherwise it could take
too long before a plate is washed, and leftover food might get stuck. Trying to hold all the plates in his hands is probably not a great idea, so Tom puts them on a table as soon as the waiter hands them over to him, and picks them up from the table again
when the time comes to pass them along to the dishwasher. There is space for only two piles of plates on the table, which will be referred to as pile 1 and pile 2. There is only one table Tom can use. Tom won last year‘s SWERC, so he is certainly capable of
optimizing for efficiency. You have to output a transcript of one possible way in which Tom might decide to organize the plates on the table during the process, given the sequence of plates and requests he receives.
Input
The input has several test cases. Each case begins with a line containing a number N (1 <=N <= 1 000), followed by N lines, which contain either DROP m or TAKE m, where m > 0 is the number of plates to
take or drop. DROP m represents that the next event is the waiter bringing m plates to Tom, so he has to drop them on the table, while TAKE m represents that the next event is Tom taking m plates from the table and passing them along in the right order. You
can assume that he never receives a TAKE m instruction when there are fewer than m plates on the table, and that the sum M of all values of m corresponding to DROP operations does not exceed 100 000. Note that there might be plates left on Tom‘s table when
the last request is issued, as Tom might be relieved of his duty to stay until the restaurant closes. The input ends with a line with N = 0, which must not be processed.
Output
For every test case, the output will be a series of lines describing the operations to be performed with the plates. The content of each line will be one of the following:
1、 DROP 1 m (DROP 2 m), m > 0, if Tom needs to take a plate from the waiter, drop it on top of pile 1 (pile 2), and repeat this operation m times in total.
2、 TAKE 1 m (TAKE 2 m), m > 0, if Tom needs to take a plate from the top of pile 1 (pile 2), pass it along to the dishwasher, and repeat m times in total.
3、 MOVE 1->2 m (MOVE 2->1 m), m > 0, if Tom needs to take a plate from the top of pile 1 (pile 2), drop it on top of pile 2 (pile 1), and repeat m times in total.
You must output at most 6N lines, and the total number of movements of plates in your transcript (that is, the sum of the m‘s printed in your output, for all three kinds of operations), must be at most 6M, as otherwise Tom won‘t be able to cope with all the
work.Note that Tom must obey the commands in the same order as they are issued. This means that, if he receives a TAKE m command, he must perform a certain number of MOVE and TAKE operations such that the sum of the numbers of plates taken adds up exactly
to m before performing the operations corresponding to the next command; and if he receives a DROP m command, he must perform a number of DROP or MOVE operations for which the sum of the nu- mbers of plates dropped adds up exactly to m before performing the
operations corresponding to the next command.Of course, it is also forbidden to take plates from the waiter or pass them along to the dishwasher in the absence of the corr- esponding order. There must be an empty line between the outputs of di erent cases.
Any solution satisfying these conditions will be accepted.
Sample Input
3 DROP 100 TAKE 50 TAKE 20 3 DROP 3 DROP 5 TAKE 8 0
Sample Output
DROP 2 100 MOVE 2->1 100 TAKE 1 50 TAKE 1 20 DROP 2 3 DROP 2 5 MOVE 2->1 8 TAKE 1 8
题意：当读到 "DROP m" 从侍者手中接过盘子 m 个盘子放在 2 号堆。当读到 "TAKE m" ，就要从 1 号堆拿出 m 个盘子给洗碗机。题意要求拿出的盘子的顺序和进来的顺序一致。这就要用到 "MOVE 1->2 t" 操作，从 1 号堆转移 t 个盘子到 2 号堆。 注意每次取盘子都是从最顶端开始拿。每两个例子间空一行。
思路：模拟。每次 1 号堆为空都要把 2 号堆的所有盘子移到 1 号堆，这样子才能够保证顺序不会出错。
<span style="font-size:18px;">#include <cstdio>
#include <iostream>
#include <cstring>
#include <cmath>
#include <string>
#include <algorithm>
#include <queue>
#include <stack>
using namespace std;
const double PI = acos(-1.0);
const double e = 2.718281828459;
const double eps = 1e-8;
char s[10];
int main()
{
//freopen("in.txt", "r", stdin);
//freopen("out.txt", "w", stdout);
int n;
int flag = 0;
while(cin>>n && n)
{
if(!flag)
flag = 1;
else
printf("\n");
int sum1, sum2, m;
sum1 = sum2 = 0;
while(n--)
{
cin>>s>>m;
if(s[0] == 'D')
{ <span><span class="comment">//遇到DROP将盘子存到2号堆，sum2+=m，同时输出 "DROP" 操作</span><span></span></span>
printf("DROP 2 %d\n", m);
sum2 += m;
}
else
{
if(sum1 >= m)
{ //如果1号堆剩下的盘子数 >= m，就直接输出 "TAKE" 操作
printf("TAKE 1 %d\n", m);
sum1 -= m;
}
else
{ //如果1号堆剩下的盘子数 < m，先把1号堆的所有盘子输出
if(sum1 > 0)
{
printf("TAKE 1 %d\n", sum1);
m -= sum1;
sum1 = 0;
} // 把2号堆的所有盘子移到1号堆
printf("MOVE 2->1 %d\n", sum2);
sum1 = sum2;
sum2 = 0; // 输出剩下的 m 值
if(m > 0)
{
printf("TAKE 1 %d\n", m);
sum1 -= m;
}
}
}
}
}
return 0;
}
</span>