The purpose of mapping and reducing for our program is to get divide the test input file into segments (<key,value> pairs), arrange the order of these pairs and sort them based on their key values.

The program is easy to compile: - compile using provided makefile: $ make - after which a simple ./mapreduce #mappers #reducers inputfile would be the streamlined commandline call. -An explanation would be- the arguments passed are the number of mappers and reducers along with the file being mapreduced.

mapper.c: - Reads the input file - map() uses emit() to insert <key,'1'> pairs into intermediateDS - writeintermediateDS writes them out to output/MapOut/Map_mapperID.txt mapreduce.c: - Uses fork() and exec() to spawn mappers and reducers - Allows for execution of mapper and reducer processes - Uses shuffle to send <key,value> pairs to reducer using hashfunction() - Waits for child processes to terminate reduce.c: - reduce() Reads mapper's created word.txt files - Counts the number of repititions of 'word' in word.txt by searching for 1's - Inserts them into a node of finalKeyValueDS - writeFinalDS() writes them out to output/ReduceOut/Reduce_reducerID.txt