Completed :D

src/main/kotlin/assignment/Assignment.kt

@@ -1,5 +1,7 @@
 package assignment
 
+import java.io.File
+
 // INSTRUCTIONS:
 // 1. Read a list of student responses from text file
 // 2. Filter students who are not covid positive
@@ -14,20 +16,59 @@ data class Response(
     val covidPositive: Boolean
 )
 
+// NOTE: I LIKE EXPLICITLY STATING TYPES AT MOST PLACES EXCEPT RANGED FOR LOOPS. ALTHOUGH INTELLIJ HELPS.
+
 fun main() {
     val responses = readResponses()
     val processedData = processResponses(responses)
     writeToFile(processedData)
 }
 
 fun readResponses(): List<Response> {
-    TODO()
+    val responseObj: MutableList<Response> = mutableListOf()
+
+    // Read the raw input
+    val inputFile: String = "src/main/kotlin/assignment/responses.txt"
+    val inputLines: List<String> = File(inputFile).readLines()
+
+    // Return a Response instance list after working with the input lines
+    for (line in inputLines.drop(1)) {
+        val str = line.split(" ")
+
+        val finalStr = str.filter { it != "" }
+
+        // Finally, add a complete Response object to the list
+        responseObj.add(Response(finalStr[1], finalStr[2].toInt(), finalStr[3], finalStr[4] == "yes"))
+    }
+
+    // return as a List
+    return responseObj.toList()
 }
 
 fun processResponses(responses: List<Response>): List<List<Response>> {
-    TODO()
+    // Filter covid positive ones out
+    val noCovid: List<Response> = responses.filter { !it.covidPositive }
+
+    // Sort them by branch and then their names
+    val sortedVal: List<Response> = noCovid.sortedWith(compareBy({ it.branch }, { it.name }))
+    val branchGroup = sortedVal.groupBy { it.branch }                // It's a Map. Too long and intellij helps
+
+    // 3 Groups
+    return  branchGroup.values.chunked(3).map { it.flatten() }
 }
 
 fun writeToFile(batches: List<List<Response>>) {
-    TODO()
+    // Get the output file ready
+    val outputFile: File = File("src/main/kotlin/assignment/batches.txt")
+    outputFile.appendText("\n--Text added by Abhinav--\n")
+
+    // append the contents to the text file
+    batches.forEachIndexed { batchIndex, batch ->
+        outputFile.appendText("Batch ${batchIndex + 1}:\n")
+
+        batch.forEachIndexed { studentIndex, student ->
+            outputFile.appendText("${studentIndex + 1}.\t${student.name}\t\t${student.rollNumber}\t\t${student.branch}\n") }
+
+        outputFile.appendText("\n")
+    }
 }

src/main/kotlin/assignment/batches.txt

@@ -23,3 +23,31 @@ Batch 3:
 5.	Nora		4123894		PHE
 6.	Owen		4898291		PHE
 7.	Ryan		9071271		PHE
+
+--Text added by Abhinav--
+Batch 1:
+1.	Chloe		4283661		CHE
+2.	Jack		5672351		CHE
+3.	Emily		4736471		CIV
+4.	Jacob		3246617		CSE
+5.	Lucy		3248462		CSE
+6.	Sophia		1263612		CSE
+
+Batch 2:
+1.	Harry		1278934		ECE
+2.	Hazel		2361718		ECE
+3.	Angel		1317382		EEE
+4.	Jasper		2366236		EEE
+5.	Clara		4328992		MAT
+6.	Eliana		9090341		MAT
+7.	Sarah		1334921		MAT
+
+Batch 3:
+1.	Kevin		4271786		MEC
+2.	Daisy		7364891		MIN
+3.	Daniel		8783261		MIN
+4.	William		4662376		MIN
+5.	Nora		4123894		PHE
+6.	Owen		4898291		PHE
+7.	Ryan		9071271		PHE
+