Sparse Table Algorithm Range Minimum Query

/ tusharroy25
github.com/mission-peace/inte...
github.com/mission-peace/inte...
In computer science, a range minimum query (RMQ) solves the problem of finding the minimal value in a sub-array of an array of comparable objects. Range minimum queries have several use cases in computer science such as the lowest common ancestor problem or the longest common prefix problem (LCP).

[@sagarcs669]

You should maybe stop asking for likes and shares. No one in their good sense will dislike this video. You truly understand the various phases of the algorithm one finds difficulty grasping and try to cover them in meticulous and illustrative examples. You deserve an award for being only one of the kind of CZcams Channel that has a whole lot of algorithm explanation. Awesome Sir!

[@Nikita-xk9fc]

114k subscribers are very less for u.I haven't seen ny video with this level of explanation.superb xplanation

[@jfcahoon]

Just wanted to say thank you for all the work you've put into these videos and explanations. Your work has helped me immensely and I really appreciate it.

[@nitinjain1325]

khatarnak tarike se dhulai karte hai aap algorithms ki...use chupne ki jagah nahi milti.... u r great sir ji

[@vineetsharma7287]

Great Explanation! Your videos are helping dev community a lot.

[@nguyenducvuanh48]

Thank you sir! I would have given up on the problem without this video.

[@aayushbaniyal2124]

thanks for the videos... they were really helpful ... just know that because of you many students didn't got supply in algorithm course

[@dvnsravan]

Thanks for the explanation Tushar!

[@thesavagetrader3681]

Thanks sir for your great effort... very simple and easy explanation.

[@imyashdeepsharma]

That was very good explanation , cleared some of my doubts ! Thanks Tushar Sir :)

[@user-mi5du2ez3b]

I love this, great work sir

[@ramakrishnachowdary3378]

Wow , such a clean explanation , Thank You 💙

[@utuk123]

Awesome video Tushar sir

[@anhdungoan2679]

This video is really useful, thank you very much, some people mistakenly thought the dislike button was a download button :D

[@sarthakgaba1583]

Superbly Amazing! Thanks mate :)

[@christy_yinyan8449]

Thank you so much! always the best!!!!

[@AbhishekKumar-zz3ts]

sweet and simple explanation , keep it up :D

[@pritommitchellrodrigues3724]

Thanks bhai, finally understood how it works. :D

[@shivamchauhan3562]

Thank you. Very nice explanation.

[@AmanGarg95]

Hi Tushar. If we were to do point updates at an index, then we would update all those entries at which the index in picture might contribute as a minimum to, right? This would be O(N logN) for N such point update queries. Am I correct in saying this?

[@madhav3444]

Best explanation !

[@RomanReigns-ds8hs]

thanks for the explanation.

[@techstuff9830]

Great one!

[@hope-jh7bv]

Thank you so much sir.

[@ZiadxKabakibi]

great as usual :D

[@raj1307]

great video sir :)

[@sahilgarg750]

can we use sparse table for max min range query in a 2d array(matrix)?

[@ShubhamJoshishubhamjoshi]

Thanks a lot :D could you please add one of LCA By RMQ also.

[@abubakarismail5436]

Weldone bruh Thanks

[@sushmitagoswami2033]

while doing the range query, why are we moving by k after we find the min in [query_L, K]? Since, we have already calculated for 2^k number of elements?

[@uNabL3]

Thank you!

[@RomanReigns-ds8hs]

for range queries problems. which algorithm would be better?

[@yuunpeeto8293]

many thanks!

[@front-rud]

Thank you bro!

[@harshitgangwar1426]

good explanation

[@immanuelsamuelgwu]

Correct me If I'm wrong according to the sparse table being taught when i=4, j=0 in the first column, j will be 6 and i will be 7 and the min of both is 6 so the index of the 6 which is 1 should be returned right?

[@mousatat7392]

thank you very much

[@s_cube8543]

Explanation of pseudo code at the end is what i love most in your videos.. literally it saved hours of my effort for understanding how this algos work.. and all these bcz u put days of effort into building this awesome videos. Such clean and clear explanations with examples. Thank you sooo much!! Hats off to you.
Please keep uploading more. Also if possible put links to some problems related to this algos to practise. Thanks once again!

[@techgianttechyforever]

thanks a lot sir :)

[@umangmalhotra1222]

Hi tushar! what is the logic behind putting index of minimum numbers in table , you could have directly put the minimum value direct in the table.
BTW nice video as always.

[@serhiypidkuyko4206]

Hi Tushar.
Thank you for your video.
I think for your viewers would be useful to explain the main idea of the algorithm with a sparse table.
And this is as following:
any range-interval [u,v] to divide onto two intersecting intervals [u,u+2^k-1] and [v+1-2^k,v] of length 2^k
these two intervals are intersecting because by choice: 2^k

[@vaibhavsharma8150]

thanku sir

[@somnathgiri3245]

good

[@rajbansal787]

respect++

[@rahulbhati3079]

can you upload some questions related to it

[@ravinapit1625]

Nice explanation. But Plz use another marker

[@syedashamimakter3231]

cout

[@samprasdsouza6993]

is this MO's algo ??

[@Ashley_montz]

does anyone know which problem in leetcode this is ?

[@bharatgulati8531]

wanted to give a double like to the video. but alas youtube restricted me two just one like.

[@Himanshu-ed3mf]

Important point : if we have to find out sum of elements in range [L, R], then sparse table will give time complexity O(log N) not O(1)

[@techgianttechyforever]

Is it only me who listen keyboard smashing sound when he write something on board

[@raghuramkarra15]

number of columns should be floor(log2(n))

[@RomanReigns-ds8hs]

why??

[@ujjwalbansal1070]

@@RomanReigns-ds8hs cp-algorithms.com/data_structures/sparse-table.html Read the Intuition part of the above link

[@sgulugulu19]

Wouldn't it be more helpful if we store the elements directly..rather than their index

[@dhruvreshamwala511]

Exactly what I was wondering

[@dhruvreshamwala511]

Okay.. Got it.. The application of RMQ demands the storage of indices.. Because, usually, the minimum value is not just "Needed", it can also be updated.

[@mayurkulkarni755]

The time complexity to query RMQ Sparse Table in your implementation is log*(n) (not to be confused with log(n), log*(n) is iterated logarithm) which can be reduced to O(1) by choosing 2 [L,R] values such that they cover all the nodes. Read this for more www.topcoder.com/community/data-science/data-science-tutorials/range-minimum-query-and-lowest-common-ancestor/#Lowest%20Common%20Ancestor%20(LCA)

[@prudvim3513]

Hi tushar, I think Segment tree takes O(n log(n)) space and time for pre processing. Not O(N)

[@saikumark6327]

the preprocessing time is o(nlogn)

[@madankumarrajan1028]

This is O(N) just the same way a heap construction algorithm takes O(N).

[@malharjajoo7393]

@@madankumarrajan1028 Can you elaborate ? From my understanding, the heap construction algorithm time complexity is not very straight-forward to understand.
Also, segment tree should be O(nlogn) according to me, since we use divide and conquer and then sum (in case of Range sum queries) the two child node values.

[@samiulislamdurjoy]

G 17:23

[@yeeroj]

Tushar bhai angrejo ki tarah English kyun bol rhe ho.....indian style English bol lo

[@ShubhamKumar-rt8nb]

first of all you should explain the logic or why we are doing something