Introduction to C++ Test 2 Lab solution

test_2_lab.cpp

/* Introduction to C++ Test 2 Lab solution by Dillon Morse
 * -------------------------------------------------------
 * a) Write a program that will create a file that will contain
 * the data values:
 * 4 -9 7
 * 1 -1 8
 * 7 4 5
 * 9 0 -3
 * when your program completes.
 *
 * b) Now, reopen your data and find the largest value stored.
 */

#include <fstream>
#include <iostream>
#include <cstring>

using namespace std;

void out();
int in();

int main() {
  string state;
  int output;
  ifstream check_ran;

  // See if the code already ran
  check_ran.open( "ran.txt" );
  if( strcmp(state.c_str(), "true") ) {
    output = in();
    cout << output << '\n';
  } else out();
}

void out() {
  ofstream file;

  // Verify that the code already ran
  file.open( "ran.txt" );
  file << "true\n";
  file.close();

  file.open( "out.txt" );
  file << "4 -9 7\n" << "1 -1 8\n" << "7 4 5\n" << "9 0 -3\n";
}

int in() {
  int largest = 0;
  int num;
  ifstream file;

  file.open( "out.txt" );
  while( file >> num ) {
    if( num > largest ) largest = num;
  }

  return largest;
}