(Solved) : Make Compatible Older C Compilers Make Use Stoi Tostring Booking System Include Include In Q37302205 . . . .

How can I make this compatible with older C++compilers that DO NOT make use of stoi and to_string?

//Booking system

#include <iostream>
#include <iomanip>
#include <string>

using namespace std;

string welcome();
void print_seats(string flight[]);
void populate_seats();
bool validate_flight(string a);
bool validate_seat(string a, int b);
bool validate_book(string a);
void print_ticket(string passenger[], int i);

string flights [5][52];
string passengers [4][250];

int main(){
    string seat, flight, book = “y”;
    int int_flight, p = 0, j = 0;
    int seat_number, seat_price;
    populate_seats();

    while (book == “y” || book == “Y”){
        passengers[p][0] =(welcome());

        cout << “nTheavailable travel times for flights are:” << endl;
        cout <<”    DeparttArrive” << endl;

        for (int i = 0; i< 5; i++){
           if (flights[i][51] != “50”){
           cout <<