can someone explain how these below 2 lines work to get the product of left part:
result.append(currentproduct * left)
left = left * lst[i]
thanks in advance!
Course: Educative: Interactive Courses for Software Developers
Lesson: Educative: Interactive Courses for Software Developers
Hi @jessie_Zhao, Thanks for reaching out to us.
result.append(currentproduct * left) calculates the product of all the elements to the left of the current element. left = left * lst[i] is updating the variable left which holds the product of all values to the left of the ith index.
Hope it will help, Happy coding 
thank you for commenting, but can you use a specific example list such as [1,2,3,4,5] to walk through the calculation? I can’t visualize the actual calculation based on the abstract idea. that’s where i stuck.
Course: Educative: Interactive Courses for Software Developers
Lesson: Educative: Interactive Courses for Software Developers
Hi @jessie_Zhao
My name is Shahrukh Naeem. I hope everything is going well with you. Thank you for reaching out about this. I will try my best to answer your query!
Lets take an example
Input list : [1, 2, 3, 4]
Result is an array which is empty initially.
Left variable stores 1 intially.
i is loop control variable which iterates the list elements.
When i = 0
currentproduct sets to 1.
First iteration of ele = list[0]= 1 —> currentproduct = 11 =1
Second iteration of ele = list[1]= 2 —> currentproduct = 12=2
Third iteration of ele = list[2]= 3 —> currentproduct = 23=6
Fourth iteration of ele = list[3]= 4 —> currentproduct = 64=24
currentproduct * left = 241=24 is appended in Result array at first index
left is 1
Updated left is 2
When i = 1
currentproduct resets to 1.
First iteration of ele = list[1]= 2 —> currentproduct = 12=2
Second iteration of ele = list[2]= 3 —> currentproduct = 23=6
Third iteration of ele = list[3]= 4 —> currentproduct = 64=24
currentproduct * left = 241=24 is appended in Result array at second index
left is 2
Updated left is 6
When i = 2
currentproduct resets to 1.
First iteration of ele = list[2]= 3 —> currentproduct = 13=3
Second iteration of ele = list[3]= 4 —> currentproduct = 34=12
currentproduct * left = 122=24 is appended in Result array at third index
left is 6
Updated left is 24
When i = 3
currentproduct resets to 1.
First iteration of ele = list[3]= 4 —> currentproduct = 14=4
currentproduct * left = 46 =24 is appended in Result array at fourth indexResult Array is [ 24, 24, 24 ,24 ]
I hope that this guide is helpful. Remember that I am always available via message to help you with any difficulty you might encounter.
Regards,
Happy Learning
Hi Shahrukh, thank you for elaborating it. it’s super helpful, though the result seems a bit different from in the solution provided. it helped!
Hi @jessie_Zhao
You are most welcome. I’m glad I could be a help to you today.
Cheers!
Hope you have a nice day.
Kind regards.