Question

Write a java program to read from a file “input4_02.txt” an integer N (0? N ? 100) and then read N double numbers from this file to an array. Write to file “output4_02.txt” this array but in the reverse order and also the sum of all elements in the array. For example File: “input4_02.txt” 5 1.30 2.22 4.00 17.60 3.14

File “output4_02.txt”

3.14 17.60 4.00 2.22 1.30

Sum = 28.26

Answer 1

import java.io.BufferedWriter;

import java.io.File;

import java.io.FileWriter;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.Scanner;

public class ReverseArray {

public static void main(String[] args)throws Exception {

// TODO Auto-generated method stub

Scanner scn=new Scanner(new File("C:/Users/ss/Desktop/input4_02.txt"));

//Read the entire input line

String str=scn.nextLine();

System.out.println(str);

//split it seperated by space and store in string array

String arr1[]=str.split(" ");

//Parse first string as int specifying the size of the array

int n=Integer.parseInt(arr1[0]);

float arr[]=new float[n];

float sum=0;

  

for(int i=0;i<n;i++){

//Parse each string as float and store it in float array

arr[i]=Float.parseFloat(arr1[i+1]);

sum+=arr[i];

}

for(int i=0;i<n/2;i++){

float temp=arr[i];

arr[i]=arr[n-1-i];

arr[n-1-i]=temp;

}

try{

FileWriter fr = new FileWriter("C:/Users/ss/Desktop/output4_02.txt");

BufferedWriter br = new BufferedWriter(fr);

PrintWriter out = new PrintWriter(br);

for(int i=0; i<n; i++){

out.write(arr[i]+" ");

}

out.println();

out.write("Sum = "+new Float(sum).toString());

out.close();

  

  

}

  

catch(IOException e){

System.out.println(e);

}

}

}

//Output Screen shots

02-Notepad File Edit Format View Help 5 1.30 2.22 4.00 17.60 3.14 DEY 9:13 AM 4 4/24/2018

output4_02 File Edit Format View Help 13.14 17.64.0 2.22 1.3 p.1.17.626.Ο 2.22 1. sum = 28.26 DEV 9:13 AM I..CY4) will 4/24/2018

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