CareerCup

N == N ?

Scan on a line by line basis and keep on adding to a stack.
At the end, do N pop operations to print last N lines

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;



public class Class1 {

	public static void main(String[] args) throws FileNotFoundException {
		// TODO Auto-generated method stub
		 File file = new File("C:\\Users\\yugandharr\\Desktop\\sample.txt");
	Scanner sc=new Scanner(file);
	String str="";
        int n=10;
	while(sc.hasNext()){
		
		str=sc.nextLine()+"\n"+str;
	}
	System.out.println(str);
	String[] LastN= str.split("\n",n);
		for(int i=n-1;i>=0;i--){
			System.out.println(LastN[i]);
		}
	}

}

We are going to implement the stack using single linked list

Have two pointers i and k. increment k from start till end but start incrementing i when k reaches N.
Once the file reading is completed, start printing the lines pointed by i till k-1.

package com.project.euler;

import java.io.File;
import java.io.RandomAccessFile;
import java.util.ArrayList;
import java.util.List;

public class FileReader {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		try {
			RandomAccessFile raf = new RandomAccessFile(new File("C:\\GameDevelopment\\eclipse\\artifacts.xml"), "r");
			List<String> lines = new ArrayList<String>();
			int N = 10;
			int i=0,k=0;
			String str;
			while((str = raf.readLine())!=null){
				if(k>=N){
					i++;
				}
				lines.add(str);
				k++;
			}
			
			while(i<k){
				System.out.println(lines.get(i++));
			}
			
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

}

Use a ring buffer.

package crap;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.LineNumberReader;

public class Printnthline {

	public static void main(String args[]) throws IOException {
		String line;
		int count = 0;
		LineNumberReader lnr = new LineNumberReader(new FileReader(
				"C:/Users/vinisha/Desktop/file.txt"));
		lnr.skip(Long.MAX_VALUE);
		System.out.println(lnr.getLineNumber());
		int value = lnr.getLineNumber();
		BufferedReader reader = new BufferedReader(new FileReader(
				"C:/Users/vinisha/Desktop/file.txt"));
		while ((line = reader.readLine()) != null) {
			// line = reader.readLine();
			count++;
			if (value+1 == count) {
				System.out.println("line:" + line);
			}

		}
	}

}

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
public class Test {
public static void main(String[] args) throws IOException{
File f = new File("D:/New/Myfile.txt");
FileInputStream fs = new FileInputStream(f);
int c;
while((c = fs.read())!=-1)
{
System.out.print((char)c);
}
fs.close();
}
}

very simple programe

import java.io.*;

public class fic {
public static void main(String[] args) throws IOException {

FileInputStream fi=new FileInputStream("D:/vamsi.txt");

InputStreamReader is=new InputStreamReader(fi);

BufferedReader bf=new BufferedReader(is);

while(bf.ready()){


String st=bf.readLine();

System.out.println(st);
}
}
}