Permutations - Leetcode 46 - Python

0:00 - Read the problem
0:30 - Drawing Explanation
6:08 - Coding Recursive
9:35 - Coding Iterative

leetcode 46

#neetcode #leetcode #python

[riddle-master-ruben]

This is a way better explanation than the old video. I went months with this problem unsolved because I just couldn't understand, but this explanation helped me tremendously. Thanks!

[hasferrr]

i think the backtracking solution with decision tree is more intuitive. For each recursion call, you can store the number that has already added to the Answer list into the HashSet, and for each recursion call you can skip the number that already in the HashSet

function permute(nums: number[]): number[][] {
const result = []
const dfs = (set: Set<number>, pm: number[]): void => {
if (pm.length === nums.length) {
result.push([...pm])
return
}
for (let i = 0; i < nums.length; i++) {
if (set.has(nums[i])) {
continue
}
pm.push(nums[i])
set.add(nums[i])
dfs(set, pm)
pm.pop()
set.delete(nums[i])
}
}
dfs(new Set(), [])
return result
}

[bandarupawankumar]

Thank you neetcode for again working on this problem :)

[AVGVSTVSivlivs]

Swapping indices method for this question is probably more clear and you should also review Longest Palindromic Substring question. Solutions in the other questions are quite optimal.
Thanks a lot!

[johnveracruz]

@NeetcodeIO PLS add a functionality on your site to not show the topics for the questions. want to do them in order without knowing the topic. thanks

[logn-xe]

Ok, this one's really the first problem in neetcode150 that is actually VERY easy to understand the goal but I personally find it extremely hard to implement

[vungrbk]

hey also do video for cherry pickup 1 and bst to sorted DLL

[Gomeroff]

I live in Russia, a new day has not yet begun, and you are already solving a new problem)

[kanjurer]

I actually just solved the problem yesterday lmao

[mukeshrawat]

Is it possible for you to have some sort of poll or something where we could ask for a video solution of a leetcode problem which you haven't already solved. Because there are quite a few problems which don't have a proper solution on YouTube and God knows when they will appear as POTD.