thank u for the explanation for how to think the optimise solution

Thanks for explaining in detail

man, that's thinking out of the box, great! I solved the problem with the brute force approach but I did realize "bro, this looks bad, its a O(n²) algorithm, thats no good for time" but I couldnt think of a way to solve it with O(n), thank you!

@nikoo28

9 ай бұрын

Good stuff!

Excellent explantion. Thanks

excellent explanation

Hii bruh, could you give me some efficient tips to solve problems using data structures and how can i choose efficient algorithm for solving particular probs?

Can you Explain AND xor OR problem on hackerrank in stack data structures part

nice explanation

tq sir i understood very will with u r explation

@bindhumadavalibindhu6057

Жыл бұрын

tq

amazingggggg amazingggg

Awesome

i dont understand why there is so much less views on this you explain in such a perfect manner... i was not able to understand que but i know its optimised way..to solve

@nikoo28

2 жыл бұрын

I am glad you found this helpful

@NiteenChougula-fs9ij

11 ай бұрын

Same thought.

@Homelander_30

Ай бұрын

He is goat.

If the limitation is size of input array is 100 why we took 102 size of count array?

Amazing video 😀

@nikoo28

9 ай бұрын

Thanks for the visit

Can someone confirm why the size of count array has been taken as 102 ?

How will the space complexity be 0(1) while you are creating addition freq array of size biggest number in the original array?

@nikoo28

Жыл бұрын

That is because the biggest number can only be 100. Always read the problem limits. So that means a constant space of 100 no matter the input. Hope this helps

Can anyone expalin why time complexicity is O(n) instead of O(2n) we are using 2 for loops ?

@nikoo28

11 ай бұрын

O(2n) is basically the same as O(n). Basically for small values of k O(k * n) ~ O(n)

A quick question how is efficient approach has O(n) time complexity?

@nikoo28

Ай бұрын

What should it be according to you?

How is it order of (N) since we have to populate the hashmap?

@nikoo28

2 жыл бұрын

Populating the hashmap will just require one iteration of the array. Hence it keeps the time complexity O(n).

Going ahead with your optimised solution , I've removed that nC2 calculation part and I'm adding count[num]++ to totalCount in the first for loop only. class Solution { public int numIdenticalPairs(int[] nums) { int[] count = new int[101]; int totalCount = 0; for(int num : nums) { totalCount+=count[num]++; //using the fact that count[num]++ is updated after assignment } return totalCount; }

@nikoo28

Жыл бұрын

love this approach

@Dadycalling55

Жыл бұрын

@@nikoo28 thank you, you're doing great work, keepItUp

@gopikaarulprakasam8195

6 ай бұрын

I can't understand this can you explain plz

I tried to find a pattern in which the count is appearing, and this is how I did my code. I knew about the permutation&combination method,but I couldn't remember the formula. int numIdenticalPairs(vector& nums) { unordered_mapmp; int n = nums.size(); int count =0; for(int i=0;i1){ count = count + mp[nums[i]] -1; } } return count; }

//cpp class NumberOfGoodPairs { public: int numIdenticalPairs(vector& nums) { // Calculate the frequency of each number vector count(102, 0); for (int num : nums) { count[num]++; } int totalCount = 0; // Calculate total number of pairs possible for (int i : count) { totalCount += (i * (i - 1)) / 2; } return totalCount; } };

What means of [102] in new int[102]

@nikoo28

2 жыл бұрын

That is the count array, storing the frequency/count of each integer

i*(i-1)/2 ..... this formula, i can't understand.... how it is same with combination formula

@nikoo28

Жыл бұрын

Try substituting values for a formula (i C 2) You will get the equivalent equation

@elyhahami4294

Жыл бұрын

n choose 2 = (n)!/((2!)(n-2)!) by definition -> n(n-1)/2 because n!=n(n-1)(n-2)! Which divides to 1 in the numerator and denominator

Love You Believe Me You are Doing Great. Please Help me to Understand AVL Tree. I am unable to understand how to maintain the height of it. I spend 30 days to do that but still unable to understand that.

@nikoo28

11 ай бұрын

to be very honest, if you are facing problems with AVL trees, you can leave them. They are hardly ever asked in coding interviews, and they do not have real life implementations as well. I don't yet have a video for AVL tree in the pipeline...but will try if needed.

@arslanmuhammad4190

11 ай бұрын

@@nikoo28 Thanks Sir, I have learn that 2 Days ago. And they are difficult to manage and maintain. But I was just want to Increase my logical thinking. So, Thanks for your help. Now, I will spend my time on AVL trees. Will u tell me which tree or trees are preferable to learn.

@arslanmuhammad4190

11 ай бұрын

@@nikoo28 But sir, BST is waste if it is not a AVL.

@arslanmuhammad4190

11 ай бұрын

@@nikoo28 To be honest You are great a teacher. Universities did not teach us coding. But You Thanks.

@arslanmuhammad4190

11 ай бұрын

Sir, You taught us Arrays, Linked List, Trees, Strings, DP Thanks. Sir, I have a request will you teach us graphs too.

A more optimized logic could be // Coding in Javascript function numIdenticalPairs(nums) { let count = 0 , freq = {} for(let i=0;i