106 - Array Manipulation | Arrays | Hackerrank Solution | Python

⭐️ Content Description ⭐️
In this video, I have explained on how to solve array manipulation using prefix sum technique in python. This hackerrank problem is a part of Problem Solving | Practice | Data Structures | Arrays | Array Manipulation and solved in python. The complexity of this solution is O (n+m).

Make a small donation to support the channel 🙏🙏🙏:-

#arraymanipulation #howtosolve #hackerrank #hackerranksolutions #hackersrealm #python #arrays #problemsolving #tutorial #algorithms #datastructures #programming #coding #codinginterview #education #aswin

[MrDitkovitch]

I sorta understand why we add k at index a and minus k b+1, so that we don't have to do the adding operation which takes O(n) time. But the biggest leap in intuition and logic is the largest element in the array is the running sum. That just doesn't make sense to me. Can you clarify why that is the case?

[sujaikrishnanc]

I included the print(arr) in the first function. It is causing runtime error. It works if it is excluded. All test cases gets passed.

[assortedDreamer]

That's a great solution, and I understand the logic that's great. Sometimes, we are not able to think such logic and use a complex solution, what would you recommend for that.

[cer_oz]

piece of art... i still try to understand the solution. what is time complexity of this solution?

[davidhuang]

This was my first attempt at the problem. It passes 8/15 test cases. Even though It says runtime error, I still do not know what is causing the problem. Is it because of the large numbers in some test cases.

arr=[0]*(n)

for a, b, k in queries:
for i in range(a-1, b, 1):
arr[i]=arr[i]+k

return max(arr)

[zhengxijiang]

one question i use the following code to find the max value, and some test cases cannot pass, these are big test cases, can somebody help to point out why?
for i in range(1, n+2):
arr[i]=arr[i]+arr[i-1]
return max(arr)

[anirudhjayant]

Easy to follow & Simple. Keep up the good work bro!!!

[rohitsanwariya]

is there a name for this strategy and when should we use this ?

[avinashhemanth]

why list comprehension didn't work for prefix sum it shows time limit exceeded ..? it is faster than normal for loop which is you used to find max element.

[helikopter]

what i dont understand is how come it's a 0 in the array and yet you are saying it's 200 and 200 in their spot! The printout clearly states 0s... how are the tests even passing :(
Can someone give a bit more explanation, because looks like magic to me haha

[kolla_teja]

why dont we take simply [0] * (n ) because it will have array on n elements

[gokuljs]

please suggest some books to solve problems like you

[AndresRojas-bmzv]

you can activate automatic translation in the video?

[Alphabetagama-qsqm]

arr[b+1] -= k ? can tell me why we do that