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  1. #include <iostream>
  2. #include <array>
  3. #include <string>
  4.  
  5. class HugeInteger
  6. {
  7.     // need to offer friendship to these 2 functions
  8.     friend std::istream & operator >> (std::istream & src, HugeInteger & value);
  9.     friend std::ostream & operator << (std::ostream & dest, const HugeInteger & value);
  10.  
  11. public:
  12.     //ctor that converts a "long long" into a HugeInteger
  13.     HugeInteger(long long value = 0LL); //0LL is constant literal value 0
  14.     //   of type long long
  15.     //ctor that converts a string into a HugeInteger
  16.     HugeInteger(const char *str);
  17.     //Convert a string into a HugeInteger
  18.     void input(const std::string& str);
  19.  
  20. private:
  21.     bool negative;  // will be true if number is negative
  22.     std::string hugeInt; // each digit is stored in a string object
  23. };
  24.  
  25. //overloads the << and >> operators for the HugeInteger class
  26. std::istream & operator >> (std::istream & src, HugeInteger & value);
  27. std::ostream & operator << (std::ostream & dest, const HugeInteger & value);
  28.  
  29. using namespace std;
  30.  
  31. HugeInteger::HugeInteger(long long value)
  32. {
  33.     // set all MaxDigit digits to zero to start
  34.     this->negative = false;
  35.     if (value < 0LL){ // 0LL is constant literal 0 of type long long
  36.         this->negative = true;
  37.         value = -value; // make the value positive	                
  38.     }
  39.  
  40.     unsigned int i = 0;
  41.     for (; i < hugeInt.size(); i++)
  42.     {
  43.         this->hugeInt[i] = '0';
  44.     }
  45.     this->hugeInt[i] = '\0';
  46.  
  47.     // convert individual digits of input value into a HugeInteger
  48.     for (unsigned int j = hugeInt.size() - 1; j >= 0 && value != 0LL; j--)
  49.     {
  50.         short result = value % 10;
  51.         char c = (char)result;
  52.         this->hugeInt[j] = c;
  53.         value /= 10;
  54.     }
  55.  
  56.     // test to make sure that HugeInteger was able to contain value
  57.  
  58.     if (value != 0LL){
  59.         *this = 0LL; // set to -0, to signal overflow
  60.         this->negative = true; //   Possibly should increase value assigned
  61.     }                          //   to MaxDigit to fix this problem.
  62. }
  63.  
  64. // converts string into a HugeInteger object
  65. HugeInteger::HugeInteger(const char *str)
  66. {
  67.     this->input(str); 
  68. }
  69.  
  70. void HugeInteger::input(const std::string& str)
  71. {
  72.     // assume positive for now
  73.     this->negative = false;
  74.  
  75.     // init. to all zeros first
  76.     unsigned int i = 0;
  77.  
  78.     this->hugeInt.clear();
  79.     while (i < str.size())
  80.     {
  81.         if (isdigit(str[i]))
  82.             this->hugeInt += str[i];
  83.         i++;
  84.     }
  85. }
  86.  
  87.     istream & operator>>(istream & input, HugeInteger & value)
  88.     {
  89.         string inputString;
  90.         input >> inputString;
  91.         value.input(inputString);
  92.         return input;
  93.     }
  94.  
  95.     ostream & operator << (ostream & output, const HugeInteger & value)
  96.     {
  97.         // find first non-zero digit
  98.         unsigned int i = 0;
  99.         while (i < value.hugeInt.size()){
  100.             if (value.hugeInt[i] != '0'){
  101.                 break;
  102.             }
  103.             ++i;
  104.         }
  105.  
  106.         // if all zeros, just output a single 0
  107.         if (i == 40)
  108.         {
  109.             cout << '0';
  110.             return output;
  111.         }
  112.  
  113.         // check if we need to ouput a negative sign
  114.         if (value.negative){
  115.             cout << '-';
  116.         }
  117.  
  118.         // output remaining digits
  119.         for (; i < value.hugeInt.size(); i++)
  120.         {
  121.             cout << value.hugeInt[i];
  122.         }
  123.  
  124.         return output;
  125.     }
  126.  
  127.     int main()
  128.     {
  129.         HugeInteger A, B, C, D;
  130.  
  131.         // input value for A & B
  132.         cout << "****** Test << & >> operators ******\n\n";
  133.         cout << "Input values for A and B: ";
  134.         cin >> A >> B;
  135.         cout << "\nA = " << A << "\nB = " << B;
  136.         return 0;
  137.     } // end main
  138.  
  139.  
Success #stdin #stdout 0s 3280KB
comments ()
stdin
copy 
343122
65787676896845123
stdout
copy 
****** Test << & >> operators ******

Input values for A and B: 
A = 343122
B = 65787676896845123
https://ideone.com/F47TEV
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

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