cft
Become a CreatorSign inGet Started

LeetCode 560. Subarray Sum Equals K in F#

LeetCode daily problem at 2022/02/10


user

Shohei Yoshida

4 months ago | 2 min read
Follow

leetcode-560-subarray-sum-equals-k-vhx7q

URL

(1) Subarray Sum Equals K - LeetCode

Code

https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0560/main.fsx

let cumulativeList (nums: int list) =

let rec cumulativeList' nums acc =

match nums with

| [] -> acc |> List.rev |> List.tail

| head :: tail ->

let v = head + (List.head acc)

cumulativeList' tail (v :: acc)

cumulativeList' nums [ 0 ]

let subarraySum (nums: int list) (k: int) : int =

let rec subarraySum' cums k m acc =

match cums with

| [] -> acc

| head :: tail ->

match Map.tryFind (head - k) m with

| None ->

match Map.tryFind head m with

| None -> subarraySum' tail k (Map.add head 1 m) acc

| Some w -> subarraySum' tail k (Map.add head (w + 1) m) acc

| Some v ->

match Map.tryFind head m with

| None -> subarraySum' tail k (Map.add head 1 m) (acc + v)

| Some w -> subarraySum' tail k (Map.add head (w + 1) m) (acc + v)

let cums = cumulativeList nums

let m = Map.empty |> Map.add 0 1

subarraySum' cums k m 0

Upvote


user
Created by

Shohei Yoshida

Follow

A programmer of DeNA

A Programmer


people
Post

Upvote

Downvote

Comment

Bookmark

Share


Related Articles