Question

C++
1. Modify the code from your HW2 as follows:
 Your triangle functions will now return a string object. This string will contain the identification of the triangle as one of the following (with a potential prefix of the word “Right ”):
Not a triangle
 Scalene triangle
 Isosceles triangle
 Equilateral triangle

 2. All output to cout will be moved from the triangle functions to the main function.
 3. The triangle functions are still responsible for rearranging the values such that c is at least as large as the other two sides. 
4. Please run your program with all of your test cases from HW2. The results should be identical to that from HW2. You must supply a listing of your program and sample output





CODE right now 
#include <cstdlib>  //for exit, atoi, atof
#include <iostream> //for cout and cerr
#include <iomanip>  //for i/o manipulation
#include <cstring>  //for strcmp
#include <cmath>    //for fabs

using namespace std;

//triangle function
void triangle(int a, int b, int c)
{
  if (a + b <= c || a + c <= b || b + c <= a) //conditions for an invalid triangle
    cout << a << " " << b << " " << c << " "
         << "Not a triangle";
  else //if above returned false, then it is a valid triangle
  {
    int temp;

    cout << a << " " << b << " " << c << " "; //print the side values

    //logic to find out the largest value and store it to c.
    if (a > b && a > c)
    {
      temp = a;
      a = c;
      c = temp;
    }
    else if (b > a && b > c)
    {
      temp = b;
      b = c;
      c = temp;
    }

    if (a == b && b == c) //condition for equilateral triangle
    {
      cout << "Equilateral triangle";
      return;
    }

    else if (a * a == b * b + c * c ||
             b * b == c * c + a * a ||
             c * c == a * a + b * b) //condition for right triangle i.e. pythagoras theorem
      cout << "Right ";

    if (a == b || b == c || a == c) //condition for Isosceles triangle
      cout << "Isosceles triangle";
    else //if both the above ifs failed, then it is a scalene triangle
      cout << "Scalene triangle";
  }
}

//overloaded triangle function
void triangle(double a, double b, double c)
{
  //equality threshold value for absolute difference procedure
  const double EPSILON = 0.001;

  if (a + b <= c || a + c <= b || b + c <= a) //conditions for an invalid triangle
    cout << fixed << setprecision(5)
         << a << " " << b << " " << c << " "
         << "Not a triangle";
  else //if above returned false, then it is a valid triangle
  {
    double temp;

    cout << fixed << setprecision(5)
         << a << " " << b << " " << c << " "; //print the side values

    //logic to find out the largest value and store it to c.
    if (a > b && a > c)
    {
      temp = a;
      a = c;
      c = temp;
    }
    else if (b > a && b > c)
    {
      temp = b;
      b = c;
      c = temp;
    }

    if (fabs(a - b) < EPSILON &&
        fabs(b - c) < EPSILON) //condition for equilateral triangle
    {
      cout << "Equilateral triangle";
      return;
    }

    else if (fabs((a * a) - (b * b + c * c)) < EPSILON ||
             fabs((b * b) - (c * c + a * a)) < EPSILON ||
             fabs((c * c) - (a * a + b * b)) < EPSILON) //condition for right triangle i.e. pythagoras theorem
      cout << "Right ";

    if (fabs(a - b) < EPSILON ||
        fabs(b - c) < EPSILON ||
        fabs(a - c) < EPSILON) //condition for Isosceles triangle
      cout << "Isosceles triangle";
    else //if both the above ifs failed, then it is a scalene triangle
      cout << "Scalene triangle";
  }
}

//main function
int main(int argc, char **argv)
{
  if (argc == 3 || argc > 5) //check argc for argument count
  {
    cerr << "Incorrect number of arguments. " << endl;
    exit(1);
  }

  else if (argc == 1) //if no command arguments found then do the following
  {
    int a, b, c;        //declare three int
    cin >> a >> b >> c; //read the values

    if (a <= 0 || b <= 0 || c <= 0) //if values are negative then exit
    {
      cerr << "Data must be a positive integer. " << endl;
      exit(1);
    }
    triangle(a, b, c); //call the function if inputs are valid
  }

  else //if command arguments were found and valid
  {
    if (strcmp(argv[1], "-i") == 0)
    {
      int a, b, c, temp; //declare required variables

      if (argc == 5)
      {
        //convert char to int using atoi()
        a = atoi(argv[2]);
        b = atoi(argv[3]);
        c = atoi(argv[4]);
      }
      else
      {
        cin >> a >> b >> c; // read the values
      }

      if (a <= 0 || b <= 0 || c <= 0) //if values are negative then exit
      {
        cerr << "Data must be a positive integer. " << endl;
        exit(1);
      }

      //call the function
      triangle(a, b, c);
    }

    else if (strcmp(argv[1], "-d") == 0)
    {
      double a, b, c, temp; //declare required variables

      if (argc == 5)
      {
        //convert char to int using atoi()
        a = atof(argv[2]);
        b = atof(argv[3]);
        c = atof(argv[4]);
      }
      else
      {
        cin >> a >> b >> c; // read the values
      }

      if (a <= 0 || b <= 0 || c <= 0) //if values are negative then exit
      {
        cerr << "Data must be a positive double. " << endl;
        exit(1);
      }

      //call the overloaded function
      triangle(a, b, c);
    }
  }

  cout << endl;

  return 0;
}

Answer 1

The below code has been modified to convert the functions return type from void to string. comment as //added has been included in the modified parts of the code.

#include <cstdlib>  //for exit, atoi, atof
#include <iostream> //for cout and cerr
#include <iomanip>  //for i/o manipulation
#include <cstring>  //for strcmp
#include <cmath>    //for fabs
#include <string>

using namespace std;

//triangle function
string triangle(int a, int b, int c)
{
    string res;
    
  if (a + b <= c || a + c <= b || b + c <= a) {//conditions for an invalid triangle
  
    res = to_string(a) + " " +to_string(b)+  " "+to_string(c) + " "+ "Not a triangle";  //added
    
    return res;
  }
  else //if above returned false, then it is a valid triangle
  {
    int temp;
    res = to_string(a) + " " +to_string(b)+  " "+to_string(c) + " "; //added

    //logic to find out the largest value and store it to c.
    if (a > b && a > c)
    {
      temp = a;
      a = c;
      c = temp;
    }
    else if (b > a && b > c)
    {
      temp = b;
      b = c;
      c = temp;
    }

    if (a == b && b == c) //condition for equilateral triangle
    {
      res = res +  "Equilateral triangle"; //added
      return res;
    }

    else if (a * a == b * b + c * c ||
             b * b == c * c + a * a ||
             c * c == a * a + b * b) //condition for right triangle i.e. pythagoras theorem
      res = res +  "Right "; //added

    if (a == b || b == c || a == c) //condition for Isosceles triangle
      res = res +  "Isosceles triangle";//added 
      
    else //if both the above ifs failed, then it is a scalene triangle
      res = res +  "Scalene triangle"; //added
  }
  return res;
}

//overloaded triangle function
string triangle(double a, double b, double c)
{
  //equality threshold value for absolute difference procedure
  const double EPSILON = 0.001;
  string res;
  if (a + b <= c || a + c <= b || b + c <= a) {//conditions for an invalid triangle
    res =  to_string(a) + " " +to_string(b)+  " "+to_string(c) + " "+ "Not a triangle";  //added
    return res;
  }
  else //if above returned false, then it is a valid triangle
  {
    double temp;

    
    res =  to_string(a) + " " +to_string(b)+  " "+to_string(c) + " ";  //added

    //logic to find out the largest value and store it to c.
    if (a > b && a > c)
    {
      temp = a;
      a = c;
      c = temp;
    }
    else if (b > a && b > c)
    {
      temp = b;
      b = c;
      c = temp;
    }

    if (fabs(a - b) < EPSILON &&
        fabs(b - c) < EPSILON) //condition for equilateral triangle
    {
      res = res + "Equilateral triangle"; //added
      //return;
    }

    else if (fabs((a * a) - (b * b + c * c)) < EPSILON ||
             fabs((b * b) - (c * c + a * a)) < EPSILON ||
             fabs((c * c) - (a * a + b * b)) < EPSILON) //condition for right triangle i.e. pythagoras theorem
     // cout << "Right ";
     res = res + "Right ";

    if (fabs(a - b) < EPSILON ||
        fabs(b - c) < EPSILON ||
        fabs(a - c) < EPSILON) //condition for Isosceles triangle
        
      res = res + "Isosceles triangle";  //added
    else //if both the above ifs failed, then it is a scalene triangle 
    
      res = res + "Scalene triangle";  //added
  }
  return res;
}

//main function
int main(int argc, char **argv)
{
    
  if (argc == 3 || argc > 5) //check argc for argument count
  {
    cerr << "Incorrect number of arguments. " << endl;
    exit(1);
  }

  else if (argc == 1) //if no command arguments found then do the following
  {
     
    int a, b, c; //declare three int
    string res;   //added
    cin >> a >> b >> c; //read the values

    if (a <= 0 || b <= 0 || c <= 0) //if values are negative then exit
    {
      cerr << "Data must be a positive integer. " << endl;
      exit(1);
    }
    //call the function if inputs are valid
    res = triangle(a, b, c);
    cout<< res ;  //added
  }

  else //if command arguments were found and valid
  {
    if (strcmp(argv[1], "-i") == 0)
    {
      int a, b, c, temp; //declare required variables
      string res;

      if (argc == 5)
      {
        //convert char to int using atoi()
        a = atoi(argv[2]);
        b = atoi(argv[3]);
        c = atoi(argv[4]);
      }
      else
      {
        cin >> a >> b >> c; // read the values
      }

      if (a <= 0 || b <= 0 || c <= 0) //if values are negative then exit
      {
        cerr << "Data must be a positive integer. " << endl;
        exit(1);
      }
      
      //call the function
      res = triangle(a, b, c);
      cout<< res ;  //added
    }

    else if (strcmp(argv[1], "-d") == 0)
    {
      double a, b, c, temp; //declare required variables
      string res;

      if (argc == 5)
      {
        //convert char to int using atoi()
        a = atof(argv[2]);
        b = atof(argv[3]);
        c = atof(argv[4]);
      }
      else
      {
        cin >> a >> b >> c; // read the values
      }

      if (a <= 0 || b <= 0 || c <= 0) //if values are negative then exit
      {
        cerr << "Data must be a positive double. " << endl;
        exit(1);
      }

      //call the overloaded function
      res = triangle(a, b, c);
      cout << fixed << setprecision(5) << res;  //added
      
    }
  }

  cout << endl;

  return 0;
}

Output screenshot: