CodeCogs

Performs the multiplication of two long positive integers in the given base.

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Interface

#include <codecogs/maths/combinatorics/arithmetic/multiply.h>

using namespace Maths::Combinatorics::Arithmetic;

std::string multiply(std::string a, std::string b, int base = 10)

This function calculates the multiplication of two long <em> positive </em> integers stored as character strings, in the given numerical base. The maximum number of digits of either the numbers is only limited by the amount of memory available. The algorithm used is school multiplication and has time complexity

$O(|a| \cdot |b|)$

(1)

where $|a|$ is the length (number of digits) of a and $|b|$ is the length of b.

Example:

#include <codecogs/maths/arithmetic/multiply.h>
#include <iostream>

int main()
{
  std::string a("77723445"), b("1236174734675"),
  c = Maths::Arithmetic::multiply(a, b, 8);
  std::cout << "The following is a base 8 operation" << std::endl;
  std::cout << a << " * " << b << " = " << c << std::endl;
  return 0;
}

Output:

The following is a base 8 operation
77723445 * 1236174734675 = 123525352137151621521

Parameters

the first factor

the second factor

base

Default value = 10

Returns

a character string corresponding to the multiplication of the given numbers

Interactive Calculator

base

Result –