LeetCode 350 | Intersection of Two Arrays II | Solution Explained (Java + Whiteboard)

Today we go over the sort method to solving this problem!

Running Time: O(mlogm + nlogn)
Space Complexity: O(logm + logn)

Always be pluggin:

[fsxaviator]

Thank you!!! Finally, this was the first explanation I was actually able to understand.

[PriyamF]

Hey. The solution doesn't work for : int[] arr1 = {4, 9, 5};
int[] arr2 = {9, 4, 9, 8, 4}; please check.

[txjzidn]

Thank you. I have always wondered why there was a pre-increment and a post increment, and this is a perfect use case for post-increment. It's the small things sometimes. I've never seen that before.

[sayantaniguha]

Finally an explanation using constant space!

[HenggaoCai]

Keep up the good work! You're doing great.

[ritchievales]

I had it so close.... I was increasing the indexes depending on nums1 and nums2 sizes... that approach worked for a few testcases but I couldn't figure out until saw this video, thanks! For sure I was not able to solve it by myself but still learned a lot :)

[athangkulkarni]

At max, minimum of size of both arrays can be duplicates, so instead of doing length1 * length2, you can do min(length1, length2)

[sasgaro]

Great video, you definitely deserve more subs, one note: that music started waaaayyy too early and was kinda unexpected covering your voice over.

[bina.soche.samjhe]

why did we use nums1 and not nums2 to store the common elements

[pubamx]

Great explanation. Just wasn't clear to me why SC is O(logm + long). Is it due to the sort of arrays generates overrides the initial value of nums array or why? Thanks in advance.

[AbhishekKumar-ffvg]

how to implement the same in c++ with same space com.
i tried but more elements are getting copied can you give code for same. thanks for video

[adithyang]

What about the values which are already present in nums1 how are they getting deleted

[lighto]

Solution without using extra space is amazing thanks! Bit time complexity basically is O(N), isn't it?

[monikajha]

I am little confused about the third array(ans) size as length1 * length2. Can we take the size as the smallest of length1 and length2?

[sayantaniguha]

How is the space *O(log m + log n)* ?

[odongoemmanuel]

where are you getting the nums in return Arrays.copyOfRange(nums, 0, k);

[qianjun]

Am I missing anything, I feel this algorithm is not working.
A=[1, 2, 2, 1, 3, 2]
B=[1, 2, 3]
A_sorted=[1, 1, 2, 2, 2, 3]
expected output: [1, 2]
The Algorithm will produce[1, 2, 3]

[pqr.priyanshu]

Which software do you use as a whiteboard??
thanks

[artemvolkov]

So smart to add background music while you're unable to articulate well the n/m complexity. I've broken my ears