需要帮助将字符串中的三角形转换为数组

Question

triangle = """
75
95 64
17 47 82
18 35 87 10
20 04 82 47 65
19 01 23 75 03 34
88 02 77 73 07 63 67
99 65 04 28 06 16 70 92
41 41 26 56 83 40 80 70 33
41 48 72 33 47 32 37 16 94 29
53 71 44 65 25 43 91 52 97 51 14
70 11 33 28 77 73 17 78 39 68 17 57
91 71 52 38 17 14 91 43 58 50 27 29 48
63 66 04 68 89 53 67 30 73 16 69 87 40 31
04 62 98 27 23 09 70 98 73 93 38 53 60 04 23"""

def return_triangle(triangle,n):
    arr_start = triangle.split()
    print(arr_start)
    current_row = 1
    start_index = current_row - 1
    max_index = start_index + current_row
    triangle_array = []
    while current_row <= rows:
        print('len arr_start',len(arr_start))
        temp_arr = []
        for i in range(start_index,max_index):
            temp_arr.append(arr_start[i])
        triangle_array.append([temp_arr])
        current_row += 1
        start_index += current_row - 1
        max_index = start_index + current_row
    return triangle_array

print(return_triangle(triangle))

here is my output 
[['63', '66', '04', '68', '89', '53', '67', '30', '73', '16', '69', '87', '40', '31']]
12
[['91', '71', '52', '38', '17', '14', '91', '43', '58', '50', '27', '29', '48']]
11
[['70', '11', '33', '28', '77', '73', '17', '78', '39', '68', '17', '57']]
10
[['53', '71', '44', '65', '25', '43', '91', '52', '97', '51', '14']]
9
[['41', '48', '72', '33', '47', '32', '37', '16', '94', '29']]
8
[['41', '41', '26', '56', '83', '40', '80', '70', '33']]
7
[['99', '65', '04', '28', '06', '16', '70', '92']]
6
[['88', '02', '77', '73', '07', '63', '67']]
5
[['19', '01', '23', '75', '03', '34']]
4
[['20', '04', '82', '47', '65']]
3
[['18', '35', '87', '10']]
2
[['17', '47', '82']]
1
[['95', '64']]
0
[['75']]
0

i get up to the last n-2 rows but i cannot get the last 2 rows to print i want to know how to do that withut going out of bound in my loop. Now if i look at my expected output which is supposed to be

[[04, 62, 98, 27, 23, 09, 70, 98, 73, 93, 38, 53, 60, 04, 23]] 13 [['63', '66', '04', '68', '89', '53', '67', '30', '73', '16', '69', '87', '40', '31']] 12 [['91', '71', '52', '38', '17', '14', '91', '43', '58', '50', '27', '29', '48']] 11 [['70', '11', '33', '28', '77', '73', '17', '78', '39', '68', '17', '57']] 10 [['53', '71', '44', '65', '25', '43', '91', '52', '97', '51', '14']] 9 [['41', '48', '72', '33', '47', '32', '37', '16', '94', '29']] 8 [['41', '41', '26', '56', '83', '40', '80', '70', '33']] 7 [['99', '65', '04', '28', '06', '16', '70', '92']] 6 [['88', '02', '77', '73', '07', '63', '67']] 5 [['19', '01', '23', '75', '03', '34']] 4 [['20', '04', '82', '47', '65']] 3 [['18', '35', '87', '10']] 2 [['17', '47', '82']] 1 [['95', '64']] 0 [['75']] 0

now this is what i want but i cant seem to get this

Answer 1

  listOfStrings = [ i.split() for i in triangle.splitlines() if i ]
  listOfInt = []
  for row in listOfStrings:
      listOfInt.append( [ int(x) for x in row ] )

Answer 2

First:

For me it works if you do the following:

def return_triangle(triangle,n):

change to:

def return_triangle(triangle,rows):

Or change the rows in the while loop to n. That's an error that don't even let you run the code so maybe some copy paste error.

Second:

You have an error in your for loop. I don't know why you do -1 but it should look like this and it works:

for i in reversed(range(len(arr_triangle)-1)):

to

for i in reversed(range(len(arr_triangle))):

Don't forget the index starts with 0.

The output would look like this:

14
[['04', '62', '98', '27', '23', '09', '70', '98', '73', '93', '38', '53', '60', '04', '23']]
13
[['63', '66', '04', '68', '89', '53', '67', '30', '73', '16', '69', '87', '40', '31']]
12
[['91', '71', '52', '38', '17', '14', '91', '43', '58', '50', '27', '29', '48']]
11
[['70', '11', '33', '28', '77', '73', '17', '78', '39', '68', '17', '57']]
10
[['53', '71', '44', '65', '25', '43', '91', '52', '97', '51', '14']]
9
[['41', '48', '72', '33', '47', '32', '37', '16', '94', '29']]
8
[['41', '41', '26', '56', '83', '40', '80', '70', '33']]
7
[['99', '65', '04', '28', '06', '16', '70', '92']]
6
[['88', '02', '77', '73', '07', '63', '67']]
5
[['19', '01', '23', '75', '03', '34']]
4
[['20', '04', '82', '47', '65']]
3
[['18', '35', '87', '10']]
2
[['17', '47', '82']]
1
[['95', '64']]
0
[['75']]
0  # Output of max_sum

Since max_sum is 0 the last 0 is from maxsum the output before is from your for loop.

As a remark you can see that you have [['75']] => a list in a list.

You can eliminate this if you change this:

triangle_array.append([temp_arr])

to

triangle_array.append(temp_arr)

Answer 3

This is a more advanced solution as it is a list comprehension within a list comprehension but shows the power of Python when you get up and runnig with it.

Given your definition of name triangle above, the following code shows how it can be easily parsed into a list of lists of ints:

In [1]: [[int(item) for item in row.strip().split()]
   ...:  for row in triangle.strip().splitlines()]
Out[1]: 
[[75],
 [95, 64],
 [17, 47, 82],
 [18, 35, 87, 10],
 [20, 4, 82, 47, 65],
 [19, 1, 23, 75, 3, 34],
 [88, 2, 77, 73, 7, 63, 67],
 [99, 65, 4, 28, 6, 16, 70, 92],
 [41, 41, 26, 56, 83, 40, 80, 70, 33],
 [41, 48, 72, 33, 47, 32, 37, 16, 94, 29],
 [53, 71, 44, 65, 25, 43, 91, 52, 97, 51, 14],
 [70, 11, 33, 28, 77, 73, 17, 78, 39, 68, 17, 57],
 [91, 71, 52, 38, 17, 14, 91, 43, 58, 50, 27, 29, 48],
 [63, 66, 4, 68, 89, 53, 67, 30, 73, 16, 69, 87, 40, 31],
 [4, 62, 98, 27, 23, 9, 70, 98, 73, 93, 38, 53, 60, 4, 23]]

In [2]: 

both the uses of, (just), .strip() above could be deleted for your example string but I usually use them as it allows for spurious blank lines and spaces at the end, (and beginning), of lines.

Explanation

The outer loop is the second line of the comprehension which assigns local variable row to successive lines of triangle. The inner loop is shown as the first line of the comprehension and produces the inner list by splitting each row on whitespace and converting the resultant item to an int.