數字列表2D表格，返回表格中最大元素位置的2個數字列表

Question

該函數採用單個參數，該參數是二維數字表（數字列表列表）並返回列表2個數字表示表格中最大元素的位置。例如，最大元素是table [2] [0]，該函數返回列表[2,0]。下面是一對夫婦低於測試執行的：

到目前爲止，我有，

def maxPos2D(table): 
    l = [] 
    for i in range(len(table)): 
     for j in i: 
     if i > table: 
      continue 
      table[i][j] += 0 
    return l 

Answer 1

您可以使用itertools.chain()爲：

from itertools import chain 

def maxPos2D(table): 
    chained_list = list(chain(*table)) # create single list from table 
    max_val = max(chained_list) # find max value in list 
    max_index = chained_list.index(max_val) # find index of max value 
    columns = len(table[0]) # number of columns 
    return [max_index/columns, max_index%columns] # return [column, row] 

在你不想的情況下導入任何模塊，你可以創建一個功能爲：

def maxPos2D(table): 
    max_index_parent, max_val = 0, max(table[0]) # initialise values based 
    max_index_child = table[0].index(max_val)  # on 1st sub-list 
    for i, child in enumerate(table[1:], 1): 
     max_child_val = max(child) 
     if max_child_val > max_val: # update values based on each sub-list 
      max_index_parent, max_val = i, max_child_val 
      max_index_child = child.index(max_val) 
    return [max_index_parent, max_index_child] 

---

這是低效版本的程序，其複雜度爲O(n^2)，因爲OP可能更容易理解。 不建議進場做它：

def maxPos2D(table): 
    max_index_parent, max_index_child, max_val = None, None, None 
    for i, child in enumerate(table): 
     for j, val in enumerate(child): 
      if max_val is None or val > max_val: 
       max_index_parent, max_index_child, max_val = i, j, val 
    return [max_index_parent, max_index_child] 

採樣運行：

>>> maxPos2D([[1, 2, 4], [7, 8, 9], [4, 5, 6]]) 
[1, 2] 

Answer 2

搜索通過表和記錄的唯一的最高值，你找到

In [1]: x = [[5,3,4,22,1], [1,1,1,1,1], [4,4,4,4,4], [3,3,3,3,3]] 

In [2]: best_so_far = -999 

In [3]: for i in range(len(x)): 
    ...:  for j in range(len(x[i])): 
    ...:   if x[i][j] > best_so_far: 
    ...:    best_cords = [i,j] 
    ...:    best_so_far = x[i][j] 
    ...:    

In [4]: best_so_far 
Out[4]: 22 

In [5]: best_cords 
Out[5]: [0, 3] 

Answer 3

我認爲這可能最好將處理分成兩個單獨的函數，每個函數處理2D表格的不同維度。這樣每個只有一個目的，這使得它們各自相對容易理解。

def maxRowElement(row): 
    max_col_index, max_col_val = 0, row[0] 

    for i, val in ((i, val) for i, val in enumerate(row) if val > max_col_val): 
     max_col_index, max_col_val = i, val 

    return max_col_index, max_col_val 

def maxPos2D(table): 
    max_row_index, max_col_index, max_tbl_val = 0, 0, table[0][0] 

    for row_index, row in enumerate(table): 
     col_index, col_val = maxRowElement(row) 
     if col_val > max_tbl_val: 
      max_col_index, max_tbl_val = col_index, col_val 
      max_row_index = row_index 

    return [max_row_index, max_col_index] 


print(maxPos2D([[1]]))  # -> [0, 0] 
print(maxPos2D([[1,2]]))  # -> [0, 1] 
print(maxPos2D([[1,2], 
       [3,0]]))  # -> [1, 0] 
print(maxPos2D([[1,2,3], 
       [10,20,15], 
       [4,5,6]])) # -> [1, 1] 
print(maxPos2D([[1,2,3], 
       [10,20,15], 
       [4,5,60]])) # -> [2, 2]