3.9 Evaluation of Prefix and Postfix expressions using Stack | Data Structures

[@anthamh]

Thanks so much!! I was about to flunk my ACSL contest but then I watched this video. Thanks a lot again god bless you, madam.

[@official-ali]

you are just making our life easier. Thank you.

[@SaifulIslam-en3ji]

Hi,i love your teaching style where you have shared so technically, thanks for effective lecture on prefix and postfix.

[@HEENARANA-ij6my]

In previous video u said first we have to reverse the equation n solve from right to left but here you have directly started with right to left without reverse

[@harshyadav208]

did you found the answer ?

[@shivamchhabra7135]

Beauty with brain ❤️❤️😍 Edit 1: my comment got highlighted 😍❤️

[@keerthanarajendran988]

Thank you so much mam you are making DSA a easier subject

[@hashensenevirathna1245]

Madam you are very talented and you can teach very clearly ,this lecture series is great help to me ,thank you lot👍

[@vaishnavidongare4408]

Nice explanation !! Can u plzz give code implementation also.

[@shaileshadole8080]

no

[@supriyavarma8107]

Ma’am please make a lecture on creating a program for infix to prefix and Infix to postfix expression

[@GADDETEJESH]

mam why didn't u give codes for all this expression evaluations😔😔😔

[@sabitkondakc9147]

Thanks for the Lecture, in addition to it, "-+2*34/[16]^23" in coding it's a must to put a type brakets to define a two or more digit number, otherwise it'll fail; here an example with C# : public double EvaluatePrefixExpression(string evaluateString) { StringBuilder appendBuilder= new StringBuilder(); int length = evaluateString.Length; for (int i = length - 1; i >= 0; i--) { string c = evaluateString[i].ToString(); if (char.IsDigit(c,0)) { double term = Convert.ToSByte(c); Push(term); } else if (c=="]") { char join = evaluateString[--i]; while (join!='[') { appendBuilder.Insert(0, join); join = evaluateString[--i]; } Push(Convert.ToDouble(appendBuilder.ToString())); appendBuilder.Clear(); } else { switch (c) { case "^": double first = Pop(); double second = Pop(); double result = Math.Pow(first, second); Push(result); break; case "*": first = Pop(); second = Pop(); result = first * second; Push(result); break; case "/": first = Pop(); second = Pop(); result = first / second; Push(result); break; case "+": first = Pop(); second = Pop(); result = first + second; Push(result); break; case "-": first = Pop(); second = Pop(); result = first - second; Push(result); break; } } } return Pop(); }

[@luissalvador1348]

Wow this is so easy to understand. Thank you.

[@aayushisharma4051]

madam your teaching is very good .

[@AnishKumar-qq8yh]

Dhanyawad from andromeda galaxy

[@animefacts4007]

Dhanyabad from Nepal 💓💓💓

[@vakhariyajay2224]

Thank you very much. You are a genius. 👍👍🔝🔝👌👌🙏🙏

[@soumikpaul2413]

always feel good to learn from you

[@AkashGupta-bu3kr]

You are a great teacher mam

[@sushma2615]

Your work is really appreciatable... Thank you so much mam....

[@TahirKhan-fd8vr]

Literally mam you are fabulous 😃

[@atabhabibi8091]

Thank you so much for your help May God guide you

[@vindy11712]

Nice explanation madam 🥺❤

[@vikranthbandi5833]

your explanation is very good mam

[@shivrajsinhgohil9474]

Very clear explanation Ma'am.

[@nimraali4085]

Your teaching method isExcellent 😍

[@aniketkumar2502]

Thanks you mam for making useful video for us

[@rumiNITPatna]

amazing video mam!

[@kyliemun2681]

your explanation is really clear maam!!!!! please keep on making new videos. if possible, please do for queues in data str too:)

[@vamshikrishnam9206]

u made DSA easier

[@mehakgoyal9223]

Your lecture does wonder for my revision... Thanks jenny👍

[@V.Rchannel]

Mam -*+abc/d^ef ans is 18 solve proper plz😊

[@TheDIVINEcasteR]

the priority of ^ is 4. Right?

[@vikranthbandi5833]

what is the algorithm to infix to postfix and also infix to prefix and vice versa ??

[@Ek_e_Alfaaz]

Thanku so much for ur lectures 🙏😊

[@kishork80]

simply great :) loved it

[@justcurious1940]

Nice explanation.

[@irfanbasha7445]

Mam,Thnk u. But we also need code for dis.😜

[@ArijitsClasses]

Mam one question, Why are we using carat for calculating powers??? Isnt it used for calculating XOR operations??

[@verilog_programming]

ma'am, we can use anyone method to transform the expression , correct or not

[@code_with_me0801]

Thank you ma'am

[@meghasinha1706]

Thanks for your efforts mam

[@namangokharu2069]

Here is again a problem, 0:59 prefix is +a-*bc/d^ef

[@niharikagoulikar2921]

No,it's wrong plz check your answer

[@pravallikachinnari1047]

Naman Gokharu is correct

[@ravibisht2904]

Woow Mam your lecture are awesome and no offence I could't take my eyes 👀 from u look pretty too.. Thanks🙏🙇

[@sheikhobama3759]

Ma'am, Thank you so much..all your videos have helped me a lot.. Although I have a small doubt. (5:15) For "/168" we did 16/8 and not 1/6, but for *342 why are we doing 3*4 and not 34*2. It would be great if anyone could explain it to me. Thank You.

[@vikasbagri1225]

because 16 here is acting as a whole ( given d = 16 ), while 3 4 2 are three individual values ( given a = 2, b = 3, c = 4 ). Hope you have got your answer.

[@SachinKumar-up6jr]

😁😁😄

[@vinaykagitha6704]

Simply awesome 👌

[@prashantpandey9051]

Bhot bhdiya madam ji😇😇

[@shirishareddy2795]

mam last video 3.8 u tell prefix scan from left to right but in these lecture u tell right to left.which one is right.

[@maheshwarienmulwar2500]

You are just awesome💯

[@sd.firdose3275]

U r just amazing...mam..

[@JavaAidTutorials]

Good one..

[@c.d.premkumar6867]

4.50 how do you distinguish between single digit operand and double digit operands ?

[@gueshteklu8624]

Hello My Teacher ? Can I Ask U 1 Question??? Evaluation Of Prefix With Out Stack Is Easier Than That of Using Stack And With Out Stack I f The compiller Executes Multiple Times Why We Need Using Stack To Evaluate Such Expression? Thanks.

[@medserghini1025]

without stack the compiler need to evaluate the expression multiple times so that is time consumming process instead using stack the process will be fast because the evaluation is only once time

[@PriyanshuSharma-vf6su]

amazing explanations

[@pradipathawale8285]

Mam, 2^2^2^2 evaluate this using prefix please..There are getting two answers, 256 and 65,536, So, kindly solve my difficulty. First convert into prefix

[@nikhilpachkor8349]

Nice Explanation

[@laplacesdemon8140]

excellent work

[@weareindians8731]

Thank you mam. And mam you are looking beautiful

[@nishanty7392]

Love u Mam 😘❤

[@ayesha24237]

Power has lower precedence than divide so why its come before / and -

[@arshpreet805]

Mam a+b*c-d/e^f and am getting prefix ^-+a*bc/def if am doing wrong please correct me......

[@shekapuramrutvik295]

Mam the evaluation is working only for single digit(i.e. evaluation using stacks). Is there anyway for doing on multidigit operands using stacks?

[@bigk2367]

IT CAN WORK FOR BOTH BROTHER.

[@BTECH-j1v]

mam's now hits hard

[@abdulwahabkhan5260]

Thanks a lot miss.

[@sparkindness]

Mam how to give a=2, b=3,c=4, d=16 e=2 f=3please tell me all time the value is same And also tell me ABC+* DE/- what is the value of A and B,C,D E only and how to take that plz mam my exams are soon so i expecte to reply me

[@mdmahfuzarrahman2322]

Wonderful explanation ♥ ♥ ♥ ♥

[@prajyotdeshpande6602]

What is precedence of "%" symbol?

[@shekshub4760]

Modulus

[@samsaikia5949]

Do we have to follow operator precedence ?

[@gd7474]

Awesome😇

[@ranjeetrathaur9378]

Thanks ma'am! ❤️

[@coder4861]

please tell the answer of this question mam evaluate the expression below expression using prefix form 2 3 9 * + 2 3 ^ - 6 2 / +

[@coder4861]

please give solution of this question mam this question is of aktu 2020-21

[@divyamadival9781]

Thank u soo much

[@SounakKaran]

mam plz give the coding implementation also then it will fruitful

[@aatmakumar4631]

Nice class

[@RiteshKumar-ud7bf]

Ma'am what if there is just one operand after an operator.

[@amishss2352]

Output of the following prefix exp *+2-21/-42+-531 Plzz mam solve this ques...

[@sheetal_s5153]

I think This is invalid expression

[@amishss2352]

Thank you for reply me back..

[@amishss2352]

Actually solve hogya tha Baad main.. Output is 2

[@sheetal_s5153]

@@amishss2352 how it is solved

[@amishss2352]

Convert this prefix expression to infix expn ...then evaluate this

[@HosRo4161]

Thank you!

[@diptimitra607]

Tusi great ho ❤️

[@antarikshasharma3102]

Thank you so much mam

[@sanjanam.r1643]

Can anyone please share the code for prefix evaluation!?

[@subashpudasaini3433]

Thank you mam😍

[@nidhigupta9801]

what if we get -ve value in between as 4(-2)6/+9+13/-

[@anamitramaiti1175]

Thank you so much 😊😊😊

[@reshma4961]

Thank you💕✨

[@mashapoguajay3322]

mam why to check right to left in prefix

[@025.madhuraaher9]

Mam could share the program to evaluate prefix operation

[@subhajitde4917]

Plz mam dont look this much pretty i got distracted 😍

[@ShubhamKumar-su2wr]

Mam , how to code the priority table?

[@aryanmaniyar3475]

Thanks Mam :)

[@nikhilpattanaik-3118]

Mam if the prefix expression is -5 6 7 the what will be its result. Plz give the ans mam

[@motivationalspot1448]

1 7 is the answer.

[@thedevhacker4608]

Maam I have this Expression A + B * C ^ (X - Y * Z / ( B + 2) ) < Y * B - (C + D) &&B != ( C + A) ^ 3 How can I solve this it has comparision operator and &&

[@bigk2367]

CONDITION OPERATOR ALWASY GIVE ANSWER IN TRUE OR FALSE(1 AND 0) SO AS I THINK AFTER SOLVING BOTH SIDE YOU WILL GET TRUE OR FALSE AS YOU ARE USING && BOTH CONDITION NEED TO BE TRUE.

[@mdnoorzafirmondal7398]

Can you evaluate this postfix operation : 2 3 + 11 * /

[@vishalkumar...5971]

239*+23^-62/+ postfix using stack mam this question is not solve me so mam plz solve the question...plzzzzzz

[@HEENARANA-ij6my]

Mam i guess u didn't reverse the equation ??? For prefix

[@gauravpoosarla]

is multidigit postfix or prefix possible?

[@akashkaundal7104]

Hats off 2 u mam

[@manishshah2424]

You are GOD

[@Prologgaming]

Right

[@dhruvpatel5947]

Hii,mam, Evaluate the following postfix expression using a stack.show the stack contents. AB*CD$-EF/G/+ A=5,B=2,C=3,D=2,E=8,F=2,G=2 Please solve this question And make a video please mam

[@vikranthbandi5833]

mam can i know what is the code for the following question ?? and also what type of stack operation to be performed is it array method or linked list method which is efficient ??

[@lol-bo7ro]

Thanks

[@simransingh6137]

Thank you mam