L6. Single Number II | Bit Manipulation

Notes/Codes/Problem links under day 8 of A2Z DSA Course: takeuforward.org/strivers-a2z...
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[@charansaianisetti5436]

mind blowing explanation, i love how in depth you are teaching the concepts.

[@jjjyotijain]

amazing explanation, it took me some time to grasp the concepts of buckets but finally I understood every step. 😅😅

[@emmanuelosademe981]

Excellent explanation. Really loved the Bucket method

[@SagarKumar-yr4ky]

Wonderful explanation man. Keep up the good work.

[@_The_-_worst_]

Make playlist or videos for Competitive programming because I have completed your dsa series 😊

[@parasjeeprep3206]

how much time did it took to complete the playlist and how many videos were you watching everyday

[@adarshrai1390]

Bro there is competative programming sheet also, if you have finished that do a deep dive in stl if c++ or collections if in Java, then do math a lot, remember no tutorial can prep you for competitive programming it is just you and you have to go deep dive in it and eventually you will learn ,from some who is 2000 on Codeforces. Best of luck

[@abhisheksanwal1106]

Mastering Segment tree, BIT,dp and graph will surely put you cm or master level but surely it's gonna take a lot of time and effort.

[@AK-nj1je]

@@adarshrai1390 bro how you counter questions from the topic that you didn't covered, does that mean you have to first cover all the dsa topics and then start cp, btw congo bro, i respect your rating!!

[@fomoCoder69]

Please Update A2Z DSA Course/Sheet for this series, it helps a lot in revision

[@Mohit_Q]

kyaaa pyaar solution tha bucket wala loving ittttt

[@ArkojyotiDeyOfficial]

WILL THE BUCKET WORK IF THE NO,S ARE NOT IN CLUSTERS

[@Zeeshan_251]

@@ArkojyotiDeyOfficial Yes, Works for every possible arrangment of the elements.

[@prantikde3121]

The bucket concept was❤

[@RK-Sonide4vr]

class Solution { public: int singleNumber(vector& nums) { int ans = 0; for(int bitIndex = 0; bitIndex

[@user-ok6km9me6x]

Thank you bhaiya.

[@AkOp-bf9vm]

i never imagine that a question can have that many solutions😂😂

[@user-tk2vg5jt3l]

Thank you bhaiya

[@UECAshutoshKumar]

Thank you sir 😁

[@Rahulyadav-sd3oj]

Thank sir 🤩🤩

[@A_Myth963]

For 2nd Bucket - will go to twos if it is in ones - I think there will be a correction here that - it will go to twos if not in ones

[@vivekgohel9794]

Same Thought Bro

[@dayashankarlakhotia4943]

public int singleNumber (int[]nums){ int ones=0,twos=0; for(int num:nums){ ones=ones^(num&~twos); twos=twos^(num&~ones); } return ones; }

[@kale-lb5pr]

i have one question like i was doing dry and run on array [5,5,5,6,4,4,4] after when array element first 4 comes if we take xor with what ones contains so it technically has 6 bcoz it occured ones then when we xor 6^4 it will not remain 6 pls tell me what im doing wrong something is off i cant pinpoint pls help guys!!

[@AkOp-bf9vm]

this is not wrong the answer will be (6^4)&(~two). ones will change here but if you completely traverse whole array the ones will contain 6

[@user-kq2vd9gh3r]

For those who not understand bucket concept , forget about bits and try with numbers only to understand concept . we want to check (ones == twos)but we don't want to lose value of ones there for using ( & ~ twos )

[@gugulothsrilakshmi8729]

i didnt understand this concept can you explain

[@divyanshbhatt8273]

at 26:35 i feel you wrote and spoke correctly but earlier in rules you stated point number two as it will go to twos, if it is in ones! please confirm striver.

[@AkOp-bf9vm]

both are correct because that line is used to execute the point "num[i] will go to twos if it is in ones" . lets consider the the array be arr={2,2,2,3} step 1: ones=2 and twos=0 step 2: num[i]==2 and ones is also 2 which means we have to delete 2 from ones. now ones==0 if it the first occurrence of 2 then it should be present in ones but it is not (because ones==0) which means it is the second occurrence of 2 which means 2 is now added in twos that why we use the condition that ***it should not be present in ones*** by ~ones.

[@user-kl3qv1sc8k]

Bucket Method😍

[@shalupriyamvada5551]

Nice explanation. However I am not able to understand the bucket method yet...Does it work only for the sorted array?

[@padmaja577]

Ya similar doubt, I think the array should be sorted....

[@vardhani3748]

No it works for unsorted array as well

[@yash2275]

Can any one please tell When I am doing dry run on [1,2,3,2,3,2,3] It is giving random ans and not the desired output then how at hardware level this is giving correct answer the method was nice but why it didn't prove it's correctness in dry run ????

[@AkOp-bf9vm]

it will give desired output after the complete traversal of array may be you done some error in your calculation #include using namespace std; int main() { vector arr={1,2,3,2,3,2,3}; int ones=0,twos=0; int n=arr.size(); for(int i=0;i

[@ShashiKanthvarma-lb6xb]

ohh, i love naive solutions

[@adarshsingh4398]

[@debayanbhunia7084]

can this solution of checking bits work in case of negative numbers as well?

[@user-jo2zo9gs3b]

yes

[@AdiCode_Hub]

Can it be explained in easy way ? plz

[@chickukoshti3741]

UNABLE TO UNDERSTAND BUCKET METHOD !

[@103_debopriyoghosh_cse_by6]

Same vro😢

[@anishsingh4021]

🔥🔥🔥

[@ManishKumar-dk8hl]

yehi too chahiye tha

[@captainyedla]

17:39 that range is wrong. equalto is missing

[@modiji8706]

at 7:54 he is more serious then my carrer

[@chiragbansod8252]

that's why u are here

[@charansaianisetti5436]

i have gone through the dsa sheet but unable to find the notes, can anyone guide me where the notes exactly is

[@modiji8706]

not update yest..

[@rijumondal6876]

I sometimes wonder why he is in not from IITs, he should have a permanent seat there

[@amanverma5912]

The question and notes links are not available in the dsa sheet. Please update it!!

[@AkOp-bf9vm]

bro i am also searching for it 🤣🤣

[@factsclub4u]

❣

[@darshbothra007]

First one to comment! Excited ❤

[@utube4026]

Congratulations bro🎉🎉🎉

[@modiji8706]

kl rashtrapati bhavan aa jana prize lene

[@utube4026]

@@modiji8706 😂😂😂😂😂😂

[@kale-lb5pr]

pls tell me why in system im getting correct result even if the array is unsorted but while im doing dry and run why im just getting some random result which i dont want pls help me unveil tell me the bit manipulation trick which maybe im not able to see through my naked eyes im not able to pinpoint the mistake pls help guys!!

[@AkOp-bf9vm]

i think we add the number and also delete it if it is duplicate thats why only unique element will remain in ones

[@GoluKumar-sb2si]

at 17:20 if we take this example after sorting [ 1,1,1,2,3,3,3,4,4,4] then according to code it will give 2 and 3 as a ans ,, but ans should be only 2 so how this code is true .Can anyone explain?

[@manjeetyadav5830]

loop will not go ahead after finding 2....2 will be returned

[@AkOp-bf9vm]

no it only return ans==2 for every index we are checking we will use if(arr[i] != arr[i-1]) return arr[n-1]; it will return n-1 index value

[@manishakumari1943]

Why can't we xor each element to get the element which is occuring once?

[@artifice_abhi]

as elements are not in even number if we xor 1 1 1 2 then 1^2 will be left at the end

[@manishakumari1943]

@@artifice_abhi ok ok got it... thank you for the explanation

[@ishanmusic677]

Sir i guess at 10:45 , you have used 2 for loops , first goes from i to 31 and second goes from j to n , which is i guess wrong because according to this we are counting the bits row wise but we have to count it colum wise so our loop should be like i to n and j to 31, correct me if im wrong

[@SriyanGaming]

no, the way in the video is correct. we want to count the number of 1's in each bit position. so we need to iterate through each bit position first, and then each number from the array to count how many 1's there are. hopefully that makes sense

[@kale-lb5pr]

pls help me im not getting answer while im doing dry nd run

[@AkOp-bf9vm]

it will give desired output after the complete traversal of array may be you done some error in your calculation. #include using namespace std; int main() { vector arr={1,2,3,2,3,2,3}; int ones=0,twos=0; int n=arr.size(); for(int i=0;i

[@AkOp-bf9vm]

suggestion for you:: you can also try to get answer from chatgpt . most of the time it will find error in your code . It will save your lot of time.

[@ayushkhairnar7154]

kuch samja nahi

[@Lucifer_The_Devill]

bhai yr aisi english mt bolo ki smgh hi na aye kuch chota sa concept smjhne me itni mehnt lg gyi

[@AkOp-bf9vm]

😂😂 ha bhai sach m kabhi kabhi samjh m aana band ho jata h ,,bhai ki english to nxt lvl hai

[@kale-lb5pr]

#include using namespace std; int singleNumII(vector a,int n) { int ones=0,twos=0; int i; for(i=0;i

[@vardhani3748]

U need to take all elements thrice except one element. If u change 6 to 4.. you'll get the correct output.