You can use this:
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
void main () {
    string line;
    ifstream myfile ("example.txt"); //change this to your file's name
    if (myfile.is_open())
    {
        while ( getline (myfile,line) )
        {
            cout << line << '\n';
        }
        myfile.close();
    }
    else 
        cout << "Unable to open file"; 
}
solved Read from file C++ (Simple) [duplicate]