Question

I am trying to place a big number in a C++ variable. The number is 600851475143

I tried unsigned long long int but got an error saying it the constant was too big. I then tried a bigInt library called BigInt -> http://mattmccutchen.net/bigint/

The problem is I can’t compile the code as I get many errors regarding the lib.

undefined reference to `BigInteger::BigInteger(int)’ <– lot’s of these.

Here is my code so far:

#include 'string' #include 'iostream'        #include 'bigint/NumberlikeArray.hh' #include 'bigint/BigUnsigned.hh' #include 'bigint/BigInteger.hh' #include 'bigint/BigIntegerAlgorithms.hh' #include 'bigint/BigUnsignedInABase.hh' #include 'bigint/BigIntegerUtils.hh' using namespace std;  int main() {      //unsigned long int num = 13195;     //unsigned long long int num = 600851475143;     BigInteger num = 13195;     int divider = 2;      //num = 600851475143;      while (1) {         if ((num % divider) == 0) {             cout << divider << '\n';             num /= divider;         }         else             divider++;          if (num == 1)             break;     } } 

If I put a smaller number and don’t use the BigInt lib this program runs fine. Any help will be appreciated 😀

Answer 1

You can specify an integer literal as long by the suffix L.
You can specify an integer literal as long long by the suffix LL.

#include <iostream>  int main() {     long long num = 600851475143LL;      std::cout << num; }