1.4 Frequency Count Method

Frequency count method

Analysis of Algorithm with loops

nested loops

Sum of All elements in an array

Adding 2 Matrices

Multiplying 2 Matrices

Courses on Udemy
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Java Programming

Data Structures using C and C++

C++ Programming

[shauryasharma]

4 years in Engineering. Never understood complexity. Found books like Cormen so repelling and complicated. 12 minutes of this video- hailing your brilliance! Thank you so much Abdul Sir. You are really a learned individual and a fantastic teacher.

[omanshsharma]

5 years have passed but still there is no content on youtube that comes close to this quality, hats off to you sir!!

[andrewcenteno]

This man is my hero. I remember seeing his videos in college. Now I am a software engineer still reviewing his videos.

[anguswang]

This dude really understands algorithms so that he can explain with such clarity. Thank you for the video!

[ankushsingh-hksj]

I literally cant express my gratitude towards you sir.... a big big thank you sir u explained in a great way

[efrainrodriguezsantiago]

I am taking data structures at the moment, first week I was scared because I didn't really understand this concepts. Second week I was so lost, started reading a book and nothing, I feel more lost than what I was.

Now? I am learning and understanding everything because of you. You have passion for this and also, you have the ability to educate other's so easily. Thank you so much Abdul! You are an amazing and fantastic teacher.

[Abdullah-mgzl]

*Key Takeaways:*
- remember, runtime complexity is taking a look at how the *number of steps/instructions required* by the algorithm changes as a function of the *input size* of the algorithm
- remember, space complexity is taking a look at how *memory required* by the algorithm changes as a function of the *input size* of the algorithm
- the most straightforward way to find the number of steps/instructions required by the algorithm as a function of the input size, is to look at the pseudocode and *see how many times each instruction gets executed* . For example, some instructions will get executed just once, regardless of input size (these are usually initialization instructions). Some instructions will get executed n times (n being the input size), these instructions are generally inside a loop that loops the same number of times as the input size
- at the end, add up all the number of times each instruction is being executed, weather it be 1 time, n times, n*n times, etc
- take the biggest contributor of the resulting expression (the highest degree), that is your complexity
- you *do a similar analysis when trying to find space complexity* . See which variables the function uses. Are they scalers? If so, they only take 1 unit of space. Are they arrays? Is the array as big as the input? That takes n units of space. Are they 2d arrays, each side being the same size as the input size? That will take n*n units of space. Just try to think how much space the function will take, based on the input size.

Thanks! This was really helpful in finding out how to count the number of instructions required as a function of input size and also amount of memory units required as a function of input size, and then converting these counts to complexity notation (i.e. just keep the biggest contributer (highest degree)).

[Gurjeetsingh-ksdv]

the patience with which he teaches is appreciable.

[arijitbanerjee]

This tutorial is better than most tutorials out there on Algos.
Amazing work

[alansaldivares]

This is a thousand times better than all the Udemy courses I ever saw on CS. Not even books. Thumbs up.

[krazyninja]

Very few people have this clarity in Algorithms. Those who are good at it are working in big companies they are busy doing their work. Those who are not very good at it are left to teach us in colleges. And the popular Books were written by the experts who treat us as their colleagues and discussing with us as if we were doing research work along with them.

[studyewu]

May Allah swt increase ur ilm(knowledge) more
Thank you so much sir, for your describe

[asishraz]

In my 4 years of engineering life and 3 + yrs of IT industry experience, I never understood the time and space complexity in just 12 minutes of your video. This is a totally brilliant way of teaching. Sir, I became a big admirer of your teaching skill. This video, I am going to share at my level best, and thank you so much for making the above concept so simple and easy for us. I have never understood this topic before. Keep up the great work. I understood each and every second of this video. I paused the video and tried from my end and obviously with your way of teaching, I got the correct time and space complexity. Thank you once again, Sir. I am blown away with your simplicity in teaching Great, great Sir.

[marienzambrano]

I never understood time and space complexity, and now just in 12 minutes I already know how it works, Thank you so much!!!, You are a great teacher!!

[apbadman]

I AM A MASTERS COMPUTER SCIENCE STUDENT CURRENTLY IN SILLICON VALLEY HOWEVER I HAD PROBLEMS UNDERSTANDING TIME COMPLEXITIES, ONE OF MY FRIENDS SUGGESTED YOUR CHANNEL AND CHEERS TO YOU THAT NOW ALL MY DOUBTS ARE CLEARED AND I UNDERSTAND THE CONCEPT CLEARLY, THANK YOU PROFESSOR, GOD BLESS YOU.

[samiulislamshibly]

My heartiest prayer & greeting will be for you. (from Bangladesh)

[tiasamunshi]

Honestly sir, I don't comment on YouTube but you are the Greatest Of All Time. Been 10 years since you uploaded these videos and never have I had a concept explained so clearly to me ever. Thank you for your service to the student community sir. May you stay healthy and get whatever you want in your life because nobody deserves that more than you do

[junaidaftab-fihu]

After 6 years, Your videos are still seeing and I also find them very informative.Appreciated 👏

[shambhavitripathi]

learning becomes easy to a great extent when we get teachers like you ....the way you teach clears all my doubts with a crystal clear clarification ....thanks from the bottom of my heart....:)

[naazmahir]

I really really really like the calmness & piece with which you explain because it makes even the most complicated topics easier, i mean you don't explain with hustle & bustle, you explain everything step by step, explain it neatly & cleanly, big applause for u Sir 👍👏👏👏👏