OpenJudge

E:Heavy Transportation

总时间限制:
3000ms
内存限制:
65536kB
描述
Background
Hugo Heavy is happy. After the breakdown of the Cargolifter project he can now expand business. But he needs a clever man who tells him whether there really is a way from the place his customer has build his giant steel crane to the place where it is needed on which all streets can carry the weight.
Fortunately he already has a plan of the city with all streets and bridges and all the allowed weights.Unfortunately he has no idea how to find the the maximum weight capacity in order to tell his customer how heavy the crane may become. But you surely know.

Problem
You are given the plan of the city, described by the streets (with weight limits) between the crossings, which are numbered from 1 to n. Your task is to find the maximum weight that can be transported from crossing 1 (Hugo's place) to crossing n (the customer's place). You may assume that there is at least one path. All streets can be travelled in both directions.
输入
The first line contains the number of scenarios (city plans). For each city the number n of street crossings (1 <= n <= 1000) and number m of streets are given on the first line. The following m lines contain triples of integers specifying start and end crossing of the street and the maximum allowed weight, which is positive and not larger than 1000000. There will be at most one street between each pair of crossings.
输出
The output for every scenario begins with a line containing "Scenario #i:", where i is the number of the scenario starting at 1. Then print a single line containing the maximum allowed weight that Hugo can transport to the customer. Terminate the output for the scenario with a blank line.
样例输入
1
3 3
1 2 3
1 3 4
2 3 5
样例输出
Scenario #1:
4
来源
TUD Programming Contest 2004, Darmstadt, Germany

1. STL编程接口:
1)(多道题均可能用到)STL队列中queue.push()是在“队尾”插入,“队头”元素访问用queue.front(),并需要额外调用queue.pop()来删除“队头”元素
2)(dynamic median)STL中声明一个int元素的优先队列(缺省为最大堆)的方法:priority_queue<int> pq; 如果需要最小堆:priority_queue<int, vector<int>, greater<int> > pq; greater<int> 所在的头文件为<functional>
2. 输入输出格式:
(heavy transportation) 题意要求每个case结束之后单独输出一个空行,而样例并未体现这一点
3. 其他需要注意的地方:
(dynamic median/股票买卖)输入数据量较大,应使用scanf而不是cin,否则有可能超时
(polygon)注意 -1 % n (n为正整数) 仍为 -1

其他问题可以到提问板上提问或者直接找助教

全局题号
799
提交次数
637
尝试人数
115
通过人数
110