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三个水杯

时间限制：1000 ms | 内存限制：65535 KB
难度：4

描述

给出三个水杯，大小不一，并且只有最大的水杯的水是装满的，其余两个为空杯子。三个水杯之间相互倒水，并且水杯没有标识，只能根据给出的水杯体积来计算。现在要求你写出一个程序，使其输出使初始状态到达目标状态的最少次数。

输入

第一行一个整数N(0V2>V3 V10)表示三个水杯的体积。
第二行给出三个整数E1 E2 E3 （体积小于等于相应水杯体积）表示我们需要的最终状态。

输出

每行输出相应测试数据最少的倒水次数。如果达不到目标状态输出-1

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Fire Net

Time Limit: 2 Seconds      Memory Limit: 65536 KB

Suppose that we have a square city with straight streets. A map of a city is a square board with n rows and n columns, each representing a street or a piece of wall.

A blockhouse is a small castle that has four openings through which to shoot. The four openings are facing North, East, South, and West, respectively. There will be one machine gun shooting through each opening.

Here we assume that a bullet is so powerful that it can run across any distance and destroy a blockhouse on its way. On the other hand, a wall is so strongly built that can stop the bullets.

The goal is to place as 

blockhouses in a city as possible so that no two can destroy each other. A configuration of blockhouses is legal provided that no two blockhouses are on the same horizontal row or vertical column in a map unless there is at least one wall separating them. In this problem we will consider small square cities (at most 4x4) that contain walls through which bullets cannot run through.

The following image shows five pictures of the same board. The first picture is the empty board, the second and third pictures show legal configurations, and the fourth and fifth pictures show illegal configurations. For this board, the maximum number of blockhouses in a legal configuration is 5; the second picture shows one way to do it, but there are several other ways.

Your task is to write a program that, given a description of a map, calculates the maximum number of blockhouses that can be placed in the city in a legal configuration.

The input file contains one or more map descriptions, followed by a line containing the number 0 that signals the end of the file. Each map description begins with a line containing a positive integer 

that is the size of the city; 

will be at most 4. The next 

lines each describe one row of the map, with a '

' indicating an open space and an uppercase '

' indicating a wall. There are no spaces in the input file.

For each test case, output one line containing the maximum number of blockhouses that can be placed in the city in a legal configuration.

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勘探油田

Time Limit:1000MS Memory Limit:32768K

Description

某石油勘探公司正在按计划勘探地下油田资源。他们工作在一片长方形的地域中，首先将该地域划分为许多小正方形区域，然后使用探测设备分别探测每一块小正方形区域是否有油。若在一块小正方形区域中探测到有油，则标记为’@’，否则标记为’*’。如果两个相邻区域都为1，那么它们同属于一个石油带，一个石油带可能包含很多小正方形区域，而你的任务是要确定在一片长方形地域中有多少个石油带。 所谓相邻，是指两个小正方形区域上下、左右、左上右下或左下右上同为’@’。

Input

输入数据将包含一些长方形地域数据，每个地域数据的第一行有两个正整数m和n，表示该地域为m*n个小正方形所组成，如果m为0，表示所有输入到此结束。否则，后面m（1≤m≤100）行数据，每行有n（1≤n≤100）个字符，每个字符为’@’或’*’，表示有油或无油。每个长方形地域中，’@’的个数不会超过100。

Output

每个长方形地域，输出油带的个数，每个油带值占独立的一行。油带值不会超过100。

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