multiply

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

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Interface
Multiply
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Interface

C++

Excel

Multiply

std::stringmultiply(	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

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

(2)

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

a	the first factor
b	the second factor
base	Default value = 10

Returns

a character string corresponding to the multiplication of the given numbers

Authors

Anca Filibiu and Lucian Bentea (September 2005)

Source Code

Source code is available when you agree to a GP Licence or buy a Commercial Licence.

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