Project Euler/32 - Revision history

Unknown user: /* Iterate and Factor */

2025-04-19T13:54:19Z

Iterate and Factor

← Older revision		Revision as of 13:54, 19 April 2025
Line 54:		Line 54:

	End for		End for

			==Solution==

			Link: https://git.charlesreid1.com/cs/euler/src/branch/master/java/Problem032.java

			==Flags==

			{{ProjectEulerFlag}}

Unknown user: /* Approach */

2025-04-19T12:58:17Z

Approach

← Older revision		Revision as of 12:58, 19 April 2025
Line 17:		Line 17:
	==Approach==		==Approach==

	Set the bounds for the ~~multiplicand and multiplier~~:		===Set Bounds===

			Set the bounds for the product:

			C = 10^6 (maximum 5-digit number)

	~~(1 digit number) x (4 digit number) = (5 digit number)~~

	~~In theory, search space will be all numbers up to 4 digits. In reality, can deduce~~ the ~~range of one number based on what we choose as~~ the ~~other number~~:
			Set the bounds for the multiplicand and multiplier:

	A x B = C		A x B = C

	~~Let C = 10^6 (maximum 5-digit~~ number)		In theory, search space will be all numbers up to 4 digits. In reality, can deduce the range of one number based on what we choose as the other number

	~~Then if~~ A is a 1-digit number, B ranges up to 10^5 (maximum 4-digit number)		For example:

			If A is a 1-digit number, B ranges up to 10^5 (maximum 4-digit number)

	If A is a 2-digit number, B ranges up to 10^4 (maximum 3-digit number)		If A is a 2-digit number, B ranges up to 10^4 (maximum 3-digit number)

	etc...		etc...

			===Iterate and Factor===

			Iterate over each possible product

			For each possible product,

			Generate a list of factors

			Generate all possible ways to partition factors into 2 groups

			Compute product of each group

			Add product to set of pandigital products

			End for

Unknown user: Created page with "==Problem Statement== An n-digit number is pandigital if it makes use of all digits 1 to n exactly once Example: the 5-digit number 15234 is pandigital for digits 1 thru 5..."

2025-04-19T12:54:01Z

Created page with "==Problem Statement== An n-digit number is pandigital if it makes use of all digits 1 to n exactly once Example: the 5-digit number 15234 is pandigital for digits 1 thru 5..."

New page

==Problem Statement==

An n-digit number is pandigital if it makes use of all digits 1 to n exactly once

Example: the 5-digit number 15234 is pandigital for digits 1 thru 5

The product 7254 is pandigital, for digits 1 thru 9:

<math>
39 \times 186 = 7254
</math>

Find the sum of all products whose multiplicand/multiplier/product identity can be written as a 1 through 9 pandigital

Note that some products can be obtained in more than one way, so only include it once in the sum

==Approach==

Set the bounds for the multiplicand and multiplier:

(1 digit number) x (4 digit number) = (5 digit number)

In theory, search space will be all numbers up to 4 digits. In reality, can deduce the range of one number based on what we choose as the other number:

A x B = C

Let C = 10^6 (maximum 5-digit number)

Then if A is a 1-digit number, B ranges up to 10^5 (maximum 4-digit number)

If A is a 2-digit number, B ranges up to 10^4 (maximum 3-digit number)

etc...