2017-06-05 36 views
-1

我正在做一些項目歐盟問題來練習更多。我在問題11,我一直得到錯誤的答案。網格中最大的4個產品

這裏列出的清單:

problem_11 = [[8, 2, 22, 97, 38, 15, 0, 40, 0, 75, 4, 5, 7, 78, 52, 12, 50, 77, 91, 8], 
       [49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40, 98, 43, 69, 48, 4, 56, 62, 0], 
       [81, 49, 31, 73, 55, 79, 14, 29, 93, 71, 40, 67, 53, 88, 30, 3, 49, 13, 36, 65], 
       [52, 70, 95, 23, 4, 60, 11, 42, 69, 24, 68, 56, 1, 32, 56, 71, 37, 2, 36, 91], 
       [22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28, 66, 33, 13, 80], 
       [24, 47, 32, 60, 99, 3, 45, 2, 44, 75, 33, 53, 78, 36, 84, 20, 35, 17, 12, 50], 
       [32, 98, 81, 28, 64, 23, 67, 10, 26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70], 
       [67, 26, 20, 68, 2, 62, 12, 20, 95, 63, 94, 39, 63, 8, 40, 91, 66, 49, 94, 21], 
       [24, 55, 58, 5, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88, 34, 89, 63, 72], 
       [21, 36, 23, 9, 75, 0, 76, 44, 20, 45, 35, 14, 0, 61, 33, 97, 34, 31, 33, 95], 
       [78, 17, 53, 28, 22, 75, 31, 67, 15, 94, 3, 80, 4, 62, 16, 14, 9, 53, 56, 92], 
       [16, 39, 5, 42, 96, 35, 31, 47, 55, 58, 88, 24, 0, 17, 54, 24, 36, 29, 85, 57], 
       [86, 56, 0, 48, 35, 71, 89, 7, 5, 44, 44, 37, 44, 60, 21, 58, 51, 54, 17, 58], 
       [19, 80, 81, 68, 5, 94, 47, 69, 28, 73, 92, 13, 86, 52, 17, 77, 4, 89, 55, 40], 
       [4, 52, 8, 83, 97, 35, 99, 16, 7, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66], 
       [88, 36, 68, 87, 57, 62, 20, 72, 3, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69], 
       [4, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18, 8, 46, 29, 32, 40, 62, 76, 36], 
       [20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69, 82, 67, 59, 85, 74, 4, 36, 16], 
       [20, 73, 35, 29, 78, 31, 90, 1, 74, 31, 49, 71, 48, 86, 81, 16, 23, 57, 5, 54], 
       [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48] 
] 

下面是代碼:

def largest_product_grid(grid): 
    greatest = 0 
    patterns = [ 
     [(1, 0), (2, 0), (3, 0)], 
     [(1, -1), (2, -2), (3, -3)], 
     [(0, -1), (0, -2), (0, -3)], 
     [(0, 1), (0, 2), (0, 3)], 
     [(-1, -1), (-2, -2), (-3, -3)]] 
    for y in range(0, 19): 
     for x in range(0, 19): 
      for p in patterns: 
       product = grid[y][x] * grid[p[0][1]][p[0][0]] * grid[p[1][1]][p[1][0]] * grid[p[2][1]][p[2][0]] 
       if greatest < product: 
        greatest = product 
    return greatest 

我敢肯定它做更多的計算比它需要的,做同樣的數學幾次在x和y上進一步比我可能需要去。但我仍然得到錯誤的答案。正確的應該是:70600674.

編輯:問題:

「什麼是四個相鄰數字的相同 方向最棒的產品(上,下,左,右,或對角)在20×20格?「

我期待索引超出範圍的錯誤,但我監督了一個愚蠢的錯誤。

+4

什麼是項目歐拉問題11?這不是一個Eurler項目的支持網站。問題必須包含問題規範。 –

+0

請注意,您有五種模式可以涵蓋四個方向。您的第三個和第四個覆蓋相同的位置,但方向相反 - 一旦修復索引。 – Prune

回答

3

對於初學者,您希望您的搜索模式是x和y的函數。

product = grid[y][x] * grid[p[0][1]][p[0][0]] * grid[p[1][1]][p[1][0]] * grid[p[2][1]][p[2][0]] 

現在,無論x和y是什麼,p [0] [1]總是返回相同的值。你應該用類似的東西替換上面的行:

product = grid[y][x] * grid[y + p[0][1]][x + p[0][0]] * grid[y + p[1][1]][x + p[1][0]] * grid[y + p[2][1]][x + p[2][0]] 
+0

感嘆..沒錯,那是正確的。出於某種原因,在我腦海裏的那些地方。 –

+1

別擔心,它發生在我們最好的人身上:P –