// Created for this challenge: // https://www.sololearn.com/post/129445 // Figure Out My Value // There is a single number you need to // figure out. It is the sum of the two // numbers found by these rules: // 1. I have four digits. // 2. My digit in the thousands column has // my lowest value and they increase in each // sequential column to the ones column // having my highest digit value. // 3. My digits sum is one of my factors. // 4. My thousands to tens column is a // three digit prime number. // Idea to do this came from here: // https://www.sololearn.com/post/128588 // Function to split the number into digits. // Make a mutable copy of the number and // an empty list. While the copy has more // digits, add the current digit to the // front of the list and remove it from // the copy. Once we are done finding digits, // return an unmutable copy of the finished // list. fun breakNumber(number: Int): List { var value = number val list = MutableList(0) { 0 } while (value > 0) { list.add(0, value%10) value /= 10 } // while return list.toList() } // breakNumber // Function to get all primes below 1000. // Make an empty list. For all possible // values from 2 to 1000, for all primes // that have been found so far, if the // value can be evenly divided by the prime, // it can't be a prime so abort our prime // loop and get the next value. If our // prime loop finishes without finding a // factor, our value must be a prime so // add it to our list. Once we are done // checking values, return an unmutable copy // of the finished list. fun getPrimes(): List { val list = MutableList(0) { 0 } outer@ for (value in 2..1000) { for (prime in list) if (value%prime == 0) continue@outer list.add(value) } // for return list.toList() } // getPrimes // Function to check the following statement: // 2. My digit in the thousands column has // my lowest value and they increase in each // sequential column to the ones column // having my highest digit value. fun statement2(digits: List) = digits[0] < digits[1] && digits[1] < digits[2] && digits[2] < digits[3] // Function to check the following statement: // 3. My digits sum is one of my factors. fun statement3(number: Int, digits: List) = number%digits.sum() == 0 // Function to check the following statement: // 4. My thousands to tens column is a // three digit prime number. fun statement4(digits: List, primes: List) = (digits[0]*100+digits[1]*10+digits[2]) in primes // Main function for this challenge. Get a // list of all primes in our range. Make an // empty list. For all numbers in our range // specified by statement one, break the // number into a list of digits, and if the // remaining statements are true, we found a // winner so store it in our list. Once we // check all numbers in the range, if our // list has only two numbers, display them // and their sum. Otherwise, complain. fun main(args: Array) { val primes = getPrimes() val list = MutableList(0) { 0 } for (number in 1000..9999) { val digits = breakNumber(number) if (statement2(digits) && statement3(number, digits) && statement4(digits, primes)) list.add(number) } // for if (list.size == 2) println("${list[0]+list[1]}=${list[0]}+"+ "${list[1]}") else println("oh no...") } // main

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