this is a java program which I am working on but it has been along time since I used java and am really lost. I am suppose to code the sections which I marked in the project please help me.
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Arrays;
import java.util.Scanner;
/**
*
public class AlumniFinder {
/**
* Read in a file containing student records and create an array of Student
* objects
*
* @param file The filename
* @param num The number of students in the file
* @return An array of Student objects
*/
static Student[] readStudentsFromFile(String filename, int num) {
try (Scanner in = new Scanner(new File(filename))) {
Student[] students = new Student[num];
// YOUR CODE HERE
// Hints:
// To read a line from the file you can call
//String line = in.nextLine();
// The split method of the String class might come in handy to get the fields
return students;
} catch (FileNotFoundException e) {
e.printStackTrace();
return null;
}
}
/**
* Write an array of Student objects to a file
*
* @param students The array of Student objects to write out
* @param filename The output filename
*/
static void writeStudentsToFile(Student[] students, String filename) {
try (FileWriter out = new FileWriter(filename)) {
// YOUR CODE HERE
// Hints:
// To write a line to the file you can call
// out.write(“Hello World!” + “n”);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* Find students belonging to both groups.
*
* This function checks each student in group1 for membership in group2 by
* comparing it with every student in group2.
*
* @param group1 A group of Students
* @param group2 A group of Students
* @param numCommon number of students belonging to both groups
* @return An array of Students which belong to both group1 and group2
*/
static Student[] findCommonStudents1(Student[] group1, Student[] group2,
int numCommon) {
Student[] common = new Student[numCommon];
// YOUR CODE HERE
return common;
}
/**
* Find students belonging to both groups.
*
* This function checks each student in group1 for membership in group2 by
* doing a binary search on group2.
*
* @param group1 A group of Students
* @param group2 A group of Students
* @param numCommon number of students belonging to both groups
* @return An array of Students which belong to both group1 and group2
*/
static Student[] findCommonStudents2(Student[] group1, Student[] group2,
int numCommon) {
Student[] common = new Student[numCommon];
// YOUR CODE HERE
// Hints:
// To sort an array of Comparables you can call
//Arrays.sort(arr);
// To search for an element in a sorted array you can call
// Arrays.binarySearch(arr, element)
// if the returned index is >= 0, the element was found at that index
return common;
}
/**
* @param args
*/
public static void main(String[] args) {
/***** These files provided to help you with initial testing *****/
Student[] uc = readStudentsFromFile(“sample_uc_students.txt”, 10);
Student[] cs = readStudentsFromFile(“sample_cs_grads.txt”, 5);
final int cs_UC_GradsNumber = 2;
/***** Use these files for the output you submit *****/
//Student[] uc = readStudentsFromFile(“uc_students.txt”, 350000);
//Student[] cs = readStudentsFromFile(“cs_grads.txt”, 75000);
//final int cs_UC_GradsNumber = 25000;
long start, end;
start = System.currentTimeMillis();
Student[] common1 = findCommonStudents1(uc, cs, cs_UC_GradsNumber);
end = System.currentTimeMillis();
System.out.println(“Cross checking took ” + (end – start) / 1000.0
+ ” seconds.”);
Arrays.sort(common1);
writeStudentsToFile(common1, “cs_grads_at_uc_1.txt”);
start = System.currentTimeMillis();
Student[] common2 = findCommonStudents2(uc, cs, cs_UC_GradsNumber);
end = System.currentTimeMillis();
System.out.println(“Using binary search it took ” + (end – start)
/ 1000.0 + ” seconds.”);
Arrays.sort(common2);
writeStudentsToFile(common2, “cs_grads_at_uc_2.txt”);
}
}
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