Coding VS leetcode-solutions

Github has a good collection of cs books. You can find Cracking the Coding Interview here just click on download if preview isn't available. And while you're at it, also try some leetcoding, this book is a good supplement for that.

This is a 2D prefix sum problem (Check the problems tagged Prefix>Sum>2D in my repository).

For more problems like this, check the Permutation> Cycle section here: https://github.com/razimantv/leetcode-solutions

All my leetcode solutions are here along with tags. Find today's solutions in the latest commit.

You can't just use (index-displaced) because many positions in between might have already been removed. You need some data structure that can answer questions like "how many numbers in this range have not been removed?" and make updates like "remove this number" efficiently. I did this using a segment tree: https://github.com/razimantv/leetcode-solutions/tree/main/Solutions/M/make-array-empty

No. I used to answer a lot of programming and math questions on Quora (https://www.quora.com/profile/Raziman-T-V). I also have a GitHub repository of my LeetCode solutions (https://github.com/razimantv/leetcode-solutions)

Here is my solution: https://github.com/razimantv/leetcode-solutions/tree/main/Solutions/D/difference-between-maximum-and-minimum-price-sum

If you are interested, all my solutions (mostly C++) are here, along with tags for the algorithms/tricks I used to solve them.

Very similar to maximum profit in job scheduling. Can be done with sorting+dp with binary search: https://github.com/razimantv/leetcode-solutions/tree/main/Solutions/M/maximum-profit-in-job-scheduling

One way to solve this would be to keep a hash map of prefix sums modulo k: https://github.com/razimantv/leetcode-solutions/tree/main/Solutions/C/continuous-subarray-sum

Here is my c++ implementation of a similar problem, try to take a look.