Morris' Blog 我在摸索我存在的意義、生命的意義、內涵及價值。 沒有真正神手般的厲害，套用模式是大部分的情況。 沒那麼厲害的我存在的意義為何，襯托出神的存在？ 有時候不能怪別人不給我機會，我已經開始省思， 為什麼我沒有給別人機會的原因，而是全要靠別人。 有時候我認為我與眾不同，那是因為我做不到很多人能辦到的事情。 我聽不到、玩不起來、說得不夠明瞭、理解得不夠多， 我缺少的語文能力，就是一切一切無能的判定。 為此，我不曉得能做些對別人有幫助的事情。 我知道我自己是個不服輸的性格，但現在我不得不認輸。 我沒有能力，因此我必須認輸。 我到底來這世界作什麼？處處充滿不確定性， 而我總是無法出類拔萃，想當個一般人似乎也回不了頭了。 越強大的挑戰需要越強力的支持，而我的支持是什麼？ 最近嘗試與人談話，但都是失敗的結局，沒人能接受， 不需要言語，不需要溝通，一切所想都表達不出來。

49愛的鼓勵 6訂閱站台

Problem D
Maze
Input File: d.in

Output: Standard Output

In this problem you are given a square maze of dimension N with N*N blocks. Each block is numbered as follows:

The maze has only one entry which is at (0, 0) and only one exit which is at (N-1, N-1). From each block you can move in four directions (N, E, W, S) and the cost is 1 for each movement among the maze but collecting treasure does not require any cost.. Some blocks contain treasures that you will have to collect. Suppose there are T treasures in the maze and you have to collect at least S (S ≤ T) treasures from them. In this problem, you are requested to find an optimal way from starting location to ending location and take at least S treasures from the maze. Remember that, you can visit a block more than once if you want.

Input

The first line of the input contains three integers N (N ≤ 30), T (T ≤ 30) and S (S ≤ 10 and S ≤ T) describing the dimension of the maze, number of treasures in the maze and number of treasures that you can take. After that, there are T lines. Each line contains two numbers representing the position of the treasure in the maze. The input may contain multiple test cases and ends with three zeros for N, T and S.

Output

Each test case produces one line of output. This line should contain the output serial no as shown in the sample output and a number representing the minimum cost which is required to collect the treasures.

Sample Input                                 Output for Sample Input

Problem setter: Syed Monowar Hossain

Special Thanks: Derek Kisman

寫 A* 沒過，一直 TLE。我想下一次寫的時候，應該先抓一組近似解，然後再跑 A*。
不然 priority_queue 一直吐不出解。

那這題我最後用了 dfs + 減枝。

其實很簡單的，基本上對於點還是按照順序排序比較好，搜索起來比較可以在較早的時間得到解答。
接著就可以在得到解的時候，快速把不可能的解給剪掉。