Python Coding
Challenges

Lists & Arrays easy

Two Sum

Return indices (i, j) with i < j such that nums[i] + nums[j] == target.

dict complement

+18 pts 16m

Lists & Arrays medium

Maximum subarray (Kadane)

Find the contiguous subarray with the largest sum.

dp arrays kadane

+25 pts 20m

Lists & Arrays medium

Rotate array

Rotate a list right by k positions in place.

arrays in-place

+20 pts 18m

Lists & Arrays medium

Flatten nested list

Yield every integer from an arbitrarily nested list, depth-first.

recursion generators

+25 pts 22m

Lists & Arrays easy

Remove duplicates (sorted)

Return a sorted list with duplicates removed.

arrays two-pointer

+10 pts 10m

Lists & Arrays easy

Merge two sorted arrays

Merge two sorted arrays into one sorted array.

arrays merge two-pointer

+12 pts 12m

Lists & Arrays medium

Merge intervals

Merge all overlapping intervals and return a sorted result.

intervals sort

+30 pts 26m

Lists & Arrays medium

Product except self

Return an array where output[i] is the product of all elements except nums[i], without using division.

arrays prefix-sum

+25 pts 20m

Lists & Arrays hard

Sliding window maximum

Return the maximum of each window of size k as it slides across an array.

sliding-window deque arrays

+40 pts 35m