#3061. [Usaco2006 Open]赶集
[Usaco2006 Open]赶集
Description
Every year, Farmer John loves to attend the county fair. The fair has N booths (1 <= N <= 400), and each booth i is planning to give away a fabulous prize at a particular time P(i) (0 <= P(i) <= 1,000,000,000) during the day. Farmer John has heard about this and would like to collect as many fabulous prizes as possible to share with the cows. He would like to show up at a maximum possible number of booths at the exact times the prizes are going to be awarded. Farmer John investigated and has determined the time T(i,j) (always in range 1..1,000,000) that it takes him to walk from booth i to booth j. The county fair's unusual layout means that perhaps FJ could travel from booth i to booth j by a faster route if he were to visit intermediate booths along the way. Being a poor map reader, Farmer John never considers taking such routes -- he will only walk from booth i to booth j in the event that he can actually collect a fabulous prize at booth j, and he never visits intermediate booths along the way. Furthermore, T(i,j) might not have the same value as T(j,i) owing to FJ's slow walking up hills. Farmer John starts at booth #1 at time 0. Help him collect as many fabulous prizes as possible.
每一年,约翰都会带着他的奶牛们去赶集.集会中一共有N(1≤N≤400)个商店,第i个商店会在特定的时间Pi(0≤Pi≤109)对当时在店里的顾客送出一份精美的礼物.约翰当然得到了这个消息,于是他希望能拿到尽量多的礼物送给他的奶牛们.也就是说,他想尽可能多地在某商店发放礼物的时候,正好呆在店里.
Format
Input
-
Line 1: A single integer, N.
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Lines 2..1+N: Line i+1 contains a single integer, P(i). * Lines 2+N..1+N+N^2: These N^2 lines each contain a single integer T(i,j) for each pair (i,j) of booths. The first N of these lines respectively contain T(1,1), T(1,2), ..., T(1,N). The next N lines contain T(2,1), T(2,2), ..., T(2,N), and so on. Each T(i,j) value is in the range 1...1,000,000 except for the diagonals T(1,1), T(2,2), ..., T(N,N), which have the value zero.
第1行输入一个正整数N.接下来N行每行一个整数Pi.
接下来N^2行,输入乃,J.先输入T1,1 T1,2 T1,3…T1,N再输入T2,1 T2,2…T2,N依次类推
Output
- Line 1: A single integer, containing the maximum number of prizes Farmer John can acquire.
输出一个整数,即约翰最多能拿到的礼物的个数
Samples
Limitation
一共有4家商店.1号商店会在时间13送出一份礼物,2号商店送出礼物的时间为9,3号商店是时间19,4号商店是时间3. 约翰先在时间3走到4号商店,正好拿到送出的礼物.然后他再直接走到2号商店(不经过任何中转商店),在时间8到那儿,然后等待1单位时间,在时间9拿到商店送出的礼物后马上出发去1号商店,又正好能在时间13到达并拿到第3份礼物.