dentify the map and reduce functions of the following computational problems:

a$)$ Search for specific words in lots of documents.

b$)$ Findwhatdocumentscontainaspecificword.

c$)$ Find the source URL$$s of links in a collection of web pages.

d$)$ Assumeadatasethastheformat:$\{$date$,$company,start$\_$price,end$\_$price$\}.$Findthe

average daily gain of each company from $01/01/2013$ to $31/12/2023.$