View difference between Paste ID: nnLWkQNm and RKUUQReW

 #include <iostream>
 
 bool toNumberConv(std::string str, auto &x)
 {
     int dots = 0;
     bool num = true;
     unsigned int i = 0;
     while(i < str.length() && num)
     {
         if ((str[i] == '.') && dots == 0)
         {
             dots = 1;
         }
         else if (!isdigit(str[i]))
         {
             num = false;
         }
         i++;
     }
     if(num && dots == 0)
     {
         x = stoll(str);
         if(x <= 2147483647)
         {
             x = stoi(str);
             std::cout << "Ez egy int\n";
         }
         else
         {
             std::cout << "Ez egy long long\n";
         }
     }
     else if(num && dots == 1)
     {
         x = stod(str);
         std::cout << "Ez egy double\n";
     }
     else
     {
         x = -1;
         std::cout << "Nem sikerult a konvertalas\n";
     }
     return num;
 }
 /*
 int             stoi        -2,147,483,648 to 2,147,483,647
 long long int   stoll       -(2^63) to (2^63)-1
 double          stod
 */
 int main()
 {
     std::string str;
     std::cin >> str;
 
     long double x;
 
     bool isNum = toNumberConv(str, x);
 
     if(isNum) std::cout << x << std::endl;
     else std::cout << "Ez nem egy szam\n";
 
     return 0;
 }