Question

C++ Programming question

Problem: 5. Write a program that reads in a list of integers into an array with base type int. Provide the facility to either read this array from the keyboard or from a file, at the user's option. If the user chooses file input, the program should request a file name. You may assume that there are fewer than 50 entries in the array. Your program determines how many entries there are. The output is to be a two-column list. The first column is a list of the distinct array elements; the second column is the count of the number of occurrences of each element. The list should be sorted on entries in the first column, largest to smallest. Input: 0: Read from keyboard.(Then typing the input in the second line.) 1: Read from an input file named "input.txt". Output: Always give an output file named "Output.txt" Example: Input: Mode o: -12 3 -12 4 1 1 -12 1 -1 1 2 3 4 2 3 -12 Mode 1: input.txt-1233 (F) IR(E) (0) M 129 - 12 3 -12 4 11 -12 1-1 1 2 3 4 2 3 -12 There can be 150 entries, for instance, 16 entries in this example. Output: output.txt - 123 12() 1R(E) Count (O) V

Answer 1

Solution:

#include<iostream>

#include<fstream>

#include<stdlib.h>

using namespace std;

//driver code

int main()

{

int n = 0, count, arr[50], i = 0, j, input;

char x[50];

cout << "Enter 0 for user input and Enter 1 for file input: ";

cin >> input;

if(input == 0)

{

cout << "\nHow many numbers? ";

cin >> n;

cout << "Enter " << n << " integers:\n";

for(i = 0; i < n; i++) cin >> arr[i];

//sort the elements

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

{

for(j = 0; j <= i; j++)

{

if(arr[i] > arr[j])

{

int temp = arr[i];

arr[i] = arr[j];

arr[j] = temp;

}

}

}

//print the elemenets

cout << "\nN\tCount\n";

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

count = 1;

while(arr[i] == arr[i + 1] && i < n){

count++;

i++;

}

cout << arr[i] << "\t" << count << endl;

}

}

//choose file mode

else if(input == 1)

{

cout << "\nEnter a file name with directory: ";

cin >> x;

ifstream myFile(x);

if( !myFile)

{ // file couldn't be opened

cerr << "Error: file could not be opened" << endl;

exit(1);

}

while(myFile >> arr[i])

{

n++;

i++;

}

//sort data

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

{

for(j = 0; j <= i; j++)

{

if(arr[i] > arr[j])

{

int temp = arr[i];

arr[i] = arr[j];

arr[j] = temp;

}

}

}

//write sorted data to file

ofstream outdata;

outdata.open("output.txt");

if( !outdata )

{ // file couldn't be opened

cerr << "Error: file could not be opened" << endl;

exit(1);

}

outdata << "N\tCount\n";

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

count = 1;

while(arr[i] == arr[i + 1] && i < n){

count++;

i++;

}

outdata << arr[i] << "\t" << count << endl;

}

outdata.close();

}

else

cout<<"Invalid input!";

return 0;

}

Output with screenshot:

Mode 0:

Online C++ compiler, Online Code C++, compile C++, run C++, and hosty... save run share 6 + new repl 88 talk Sign up Files main.cpp saved 69 } clang version 7.0.0-3-ubuntu0.18.04.1 (tags/RELEASE_700/fin al) > clang++-7 -pthread -o main main.cpp } ./main Enter 0 for user input and Enter 1 for file input: 0 main.cpp input.txt D output.txt //write sorted data to file ofstream outdata; outdata.open("output.txt"); if( !outdata ) { // file couldn't be opened cerr << "Error: file could not be opened" << endl; exit(1); How many numbers? 16 Enter 16 integers: -12 33 -12 outdata << "N\tCount\n"; for(i = 0; i<n; i++){ count = 1; while(arr[i] == arr[i + 1] && i<n){ count++; i++; WN WNPIPI outdata << arr[i] << "\t" «< count << endl; -12 outdata.close(); N Count 33 1 else cout<<"Invalid input!"; return ; 4 3 2 2 2 2 i 4 -1
Mode 1:

Online C++ compiler, Online ... Code C++, compile Ch, run C++, and hosty... save run share + new repl 8a talk Sign up Files input.txt saved 1 -12 3 -12 4 1 1 -12 1 -1 1 2 3 4 2 3 -12 clang version 7.0.0-3-ubuntu0.18.04.1 (tags/RELEASE_700/fin al) ? clang++-7 pthread -o main main.cpp } ./main Enter 0 for user input and Enter 1 for file input: 1 main.cpp input.txt : Enter a file name with directory: input.txt L output.txt

Online C++ compiler, Online .. - Code C++, compile Cht, run C++, and hosty... save run share 6 + new repl 8a talk Sign up Files output.txt saved 1 2 clang version 7.0.0-3-ubuntu0.18.04.1 (tags/RELEASE_700/fin al) ? clang++-7 pthread -o main main.cpp } ./main Enter 0 for user input and Enter 1 for file input: 1 main.cpp L input.txt N Count 4 2 33 22 14 -1 1 -12 4 Enter a file name with directory: input.txt D output.txt 6 7

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