写一个 Sigma 方程

Question

我有一个等式，想用不同的值对它的结果求和。我使用 Number = input() 输入一个数字，方程根据索引从输入中获取数字。想要的索引是从 i = 1 到 i = 4。等式是：Number[i] + Number[i+1]*3 + i

例如，如果我的输入是 Number = 879463，那么首先 i = 1 : Number[1] + Number[2]*3 + 1，等于 8 + 7*3 + 1 = 30

然后 i = 2 : Number[2] + Number[3]*3 + 2 .. 等等，直到 i = 4。最后将结果求和存入total.

这是我的代码：

Number = input()

total = 0

def equation(i,Number):
    x = (Number[i] + Number[i+1]*3 + i)
    return x

for i in range(len(Number)):
    total += equation(i,Number)
    
print(total)

对于这段代码，我得到错误：

IndexError: string index out of range

我的方向是否正确？

Answer 1

# input is a string

number = input("Enter a number: ")

#  Two lists to store values, results and list of numbers

list_of_numbers = []
total = []

# List to store string values to integers

for i in number:
    list_of_numbers.append(int(i))
print(f'List = {list_of_numbers}')

# List to store values to total

for i in range(1, len(list_of_numbers)):
    result_equation = list_of_numbers[i - 1] + list_of_numbers[i] * 3 + i

    print(f'For i = {i},  {list_of_numbers[i - 1]} + {list_of_numbers[i]}*3 + {i} = {result_equation}')
    total.append(result_equation)

# Sum values
print(f'Total = {sum(total)}')

# Observation: Most of this code can  be erased as it is only used to print values on the screen.

写一个 Sigma 方程

Write a Sigma equation

python

function