Checksum
We need to check some data received from a client before it can be passed over to the data analytics team. The client sends us the raw data and a checksum, we need to verify that they match.
In order to generate the checksum from the raw data you need to find the sum of all digits that match the next digit in the list. The list is circular, so the digit after the last digit is the first digit in the list.
Examples
- 1122 produces a sum of 3 (1 + 2) because the first digit matches the second digit and the third digit matches the fourth digit
- 1111 produces 4 because each digit matches the next
- 91212129 produces 9 because the only digit that matches the next one is the last digit, 9.
Input Data
The client sent this input data:
5994521226795838486188872189952551475352929145357284983463678944777228139398117649129843853837124228353689551178129353548331779783742915361343229141538334688254819714813664439268791978215553677772838853328835345484711229767477729948473391228776486456686265114875686536926498634495695692252159373971631543594656954494117149294648876661157534851938933954787612146436571183144494679952452325989212481219139686138139314915852774628718443532415524776642877131763359413822986619312862889689472397776968662148753187767793762654133429349515324333877787925465541588584988827136676376128887819161672467142579261995482731878979284573246533688835226352691122169847832943513758924194232345988726741789247379184319782387757613138742817826316376233443521857881678228694863681971445442663251423184177628977899963919997529468354953548612966699526718649132789922584524556697715133163376463256225181833257692821331665532681288216949451276844419154245423434141834913951854551253339785533395949815115622811565999252555234944554473912359674379862182425695187593452363724591541992766651311175217218144998691121856882973825162368564156726989939993412963536831593196997676992942673571336164535927371229823236937293782396318237879715612956317715187757397815346635454412183198642637577528632393813964514681344162814122588795865169788121655353319233798811796765852443424783552419541481132132344487835757888468196543736833342945718867855493422435511348343711311624399744482832385998592864795271972577548584967433917322296752992127719964453376414665576196829945664941856493768794911984537445227285657716317974649417586528395488789946689914972732288276665356179889783557481819454699354317555417691494844812852232551189751386484638428296871436139489616192954267794441256929783839652519285835238736142997245189363849356454645663151314124885661919451447628964996797247781196891787171648169427894282768776275689124191811751135567692313571663637214298625367655969575699851121381872872875774999172839521617845847358966264291175387374464425566514426499166813392768677233356646752273398541814142523651415521363267414564886379863699323887278761615927993953372779567675
The client sent this checksum: 1393.
Constraints
You may use any language and/or framework for this exercise, you are encouraged to write one or more unit tests to confirm your results.