Pre-Computation using Prefix Sum in 1D/2D Arrays | Competitive Programming Course | EP 13

In this episode 13 of my competitive programming course, I discuss about another pre-computation technique which is Prefix Sum. In this video I explain in detail how we can optimise range sum queries using prefix sum in both 1d and 2d Arrays.

PRACTICE QUESTIONS FOR HASHING & PREFIX SUM :
EASY

EASY MEDIUM/HARD

(for some difficult questions, you might require knowledge of c++ sets/maps)

Timestamps:
Prefix Sum in 1D Arrays : (0:00)
Prefix Sum in 2D Arrays : (9:46)

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#precomputation #prefix #sum #optimise#competitiveprogramming

[iamluv]

at 18:37 its pf[i][j-1] instead of pf[j][i-1]

[exam_dost]

your first 10 videos are enough for whole competitive programming course. I have seen lots of competitive programming tutorial but the specific cp tricks are shown by you only. Amazing man.

IIIT guys are known for their deep knowledge is real.

[yourbestie]

always on time - your video uploading time complexity is O(1) and space complexity is O(full of knowledge)😁

[sarvaswamohata]

2 years and still it remains the best available resource for cp over the internet❤❤

[abhishekanantharam]

Kya baat hai😂
Kal hi I encountered a 2D prefix sum based problem in a test.
Appreciate your effor bro thanks💥

[barnikroy]

ye course 2 lakh ka he because of tutoring plus please paisa ka matt ke job aisahi bohot paying aapke couse aapke liye poor students ko gift are one of those best persons still prevailing on this earth

[husandeepsingh]

i started this playlist a week ago I really learned a lot until now and will keep learning more from this channel really liked the lectures

[sawandeepgavel]

That prefix sum of 2-D array was tricky and you explained it ❤️❤️

[AshokKumar-ixnf]

Bhaiya aapke karan mujhe Cpp se pyar ho gya thanks.... Yt me bahut saare lectures h but aapke explanation ka koyi jawab nhi isi tarah video's bnate rahye.. 🤗🤩

[Rafiqul.Islam]

Your videos are awesome... You not only help Indian students but also Bangladeshi students... One of my Indian cousin recommended me your playlist. And your way of teaching is on point. And I also shared it to my friend zone & they also liked it. Please continue this & we really enjoy your

[thegreekgoat]

My heart cries when educator like this aren't famous enough. Man, I challenge everybody here, if anybody show me better coding teacher than him, I will change my name..

[jhashivam]

Bestest ever competitive coding course on the internet 🔥👍

[AppaniMadhavi]

At 7:20 luv proved that he is a logical thinker.👏👏

[mohammadAmmar]

bro you are the pioneer of cp for me, , btw God bless u..love from Bangladesh/

[uditkatyal]

those who are getting confused with size of prefix array - for 1 based approach u must take N+1 size of array to accomodated nth index unless it will give segmentation fault (accessing the memory which we don't have)

[ShubhamChhimpa]

Must say you explained this in the best way.

[sagarbarpanda]

I am loving the course. Just a minor comment in this: In 1d array prefix sum, you have taken elements as int pf[n]. I think it should be long long int pf[n] as taken for 2d. It can exceed the int values.

[harshitrathi]

Was Waiting For This Thankyou Bro.... Keep On uploading more videos on CP

[shridharsarraf]

Luv bro, explains the most important things in the most easiest way. I'm observing growth in my CP skills, just in a week😄

[funenjoynilaypatel]

IIIT guys are known for their deep knowledge is real.