read data from file and manipulate

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

using namespace std;

int main(){

    //Declare file streams & open the file
    ifstream input;
    input.open("price.txt");

    if(input.fail())
    {
        cout << "price.txt could not be accessed!" << endl;
        exit(1);
    }

    string temp, test; //String data from file, to be converted to an double

    //Get data from file
    for(int i = 1; i <= 10; i++)
    {
        if(!input.eof()){
            getline(input,temp); //Get 1 line from the file and place into temp
            cout<< i << ". " << temp <<"\n";
            test[i] = atof(temp.c_str()); //set the test variable to the double data type of the line

        }
    }

    input.close();
    return 0;
}

The question is how can I use the data I get from the file to assign to another variable so I can use the variable guy to the whole program of c++

my txt file looks like 3.00 4.00 5.00 3.20 3.00 3.55 1.60 4.90 2.00 1.50