Write a program which prompts a user for 5 2-D (x,y) coordinates and writes them

Question

Write a program which prompts a user for 5 2-D (x,y) coordinates and writes them to a file "points.txt”, one point (x,y) coordinate pair per line.   Be sure to close the file before exiting the program. (Don’t write parentheses or put a comma, just write 2 floating point values per line.)

Write a second program to open the same file ("points.txt"), read the two vectors (10 numbers) back in, calculates whether the points are inside a circle centered at the origin with radius 20. (i.e., is the Euclidean distance (square root of sum of squares) less than 20?) Have your program print out a to the console the original coordinates, the length of each vector from the origin to the point, and whether it is inside a circle with radius 20.

Explanation / Answer

Please use DevC++ to run them

Program 1

#include<iostream>
#include<fstream>
using namespace std;
int main(int argc, char* argv[])
{
   //create an output file object
   ofstream outfile;
   float num;
   outfile.open("points.txt", std::fstream::app);   //append mode
   for(int i=0; i<5;i++)
   {
       cout<<" Enter x:";
       cin>>num;
       outfile<<num<<" ";
      
       cout<<" Enter y:";
       cin>>num;
       outfile<<num<<endl;
   }
  
   cout<<" Added data completed";
   outfile.close();   //close the file
   return 0;
}

Program 2:

#include<string>
#include<iostream>
#include<fstream>
#include<math.h>
using namespace std;
int main(int argc, char* argv[])
{
  
   ifstream fin;
   fin.open("points.txt",fstream::in);
   if(!fin)
   {
       cout<<" Unable to read file";
   }
  
   float x,y,length;
   fin.clear();
   fin.seekg(0,ios::beg);
  
  
   cout<<"x: y: length: ";
   while(fin>>x)
   {
       fin>>y;
       length=sqrt(x*x+y*y);
       if(length<=20)
       {
           cout<<x<<" "<<y<<" "<<length<<endl;
       }
   }
  
   fin.close();
   return 0;
}

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