# Project Euler

## Project Euler - Problem 17

It's been to long since I posted a solution to one of these challenges. How time flies when you're having fun.

Here's the problem:
`If the numbers 1 to 5 are written out in words: one, two, three, four, five, then there are 3 + 3 + 5 + 4 + 4 = 19 letters used in total.`

``` ```

`If all the numbers from 1 to 1000 (one thousand) inclusive were written out in words, how many letters would be used?`

Here is the python code:

`#!/usr/bin/env python ones = {'1': 'one', '2': 'two', '3': 'three', '4': 'four', '5': 'five',        '6': 'six', '7': 'seven', '8': 'eight', '9': 'nine', '0': ''} tens = {'2': 'twenty', '3': 'thirty', '4': 'forty', '5': 'fifty',        '6': 'sixty', '7': 'seventy', '8': 'eighty', '9': 'ninety'} teens = {'10': 'ten', '11': 'eleven', '12': 'twelve', '13': 'thriteen',         '14': 'fourteen', '15': 'fifteen', '16': 'sixteen', '17': 'seventeen',         '18': 'eighteen', '19': 'nineteen'} hundreds = {0: 0, 1: "onehundredand", 2: "twohundredand",            3: "threehundredand", 4: "fourhundredand",            5: "fivehundredand", 6: "sixhundredand",            7: "sevenhundredand", 8: "eighthundredand",            9: "ninehundredand" } if __name__ == "__main__":    tot = 0    for h in xrange(10):        for y in xrange(1,100):            try:                t,o = tuple(str(y))                if t is '1':                    tot += len("{h}{t}".format(h=hundreds[h], t=teens[t + o]))                else:                    tot += len("{h}{t}{o}".format(h=hundreds[h], t=tens[t],                                                  o=ones[o]))            except ValueError:                    tot += len("{h}{o}".format(h=hundreds[h], o=ones[str(y)]))    tot += len('onethousand')    print tot`

Even though I wrote it, I still look at it and think "that's not mine." It's been a long time since I wrote a for loop within a for loop. There isn't anything wrong with it, it's just not my style. This time however I wasn't really able to come up with a solution that would allow me to break out of the two for loops.

The one part of the code that I was surprised "worked" war breaking up the digits by turning the number to a string then a tuple. This allowed me to easily test an exception. This exception will only be thrown 10% of the time. While exceptions might be expensive, the other 90% of the time the code hums along without using a conditional. Everything has costs, but I think that the cost of throwing an exception 10% of the time as opposed to testing a conditional 100% of the time is a cost I'm willing to accept.

I will admit that I did not code up another solution in a different programming language. While part of that is due to being lazy - it's good for the soul once and a while - I'm also not sure how I can code this up in a functional language. I'm sure it can be done, I just don't know how (If anyone has a link or idea please share it.) But because I do like to compare things I tweaked the code to run within python 3.3.0. The differences in time are so minimal that I'm not even going to post it. If you're really inspired you can read the python 3 code here.

Questions and comments welcomed. One quick side note to my readers: I'm getting married this year (Yay!) and a lot of my free time is spent juggling and planning. So I might not be blogging as frequently as usual. Thanks for your patience.

## Project Euler: Problem 16

I'm not dead yet! I've just been insanely busy the last month or two with changing jobs and preparing my first programming presentation for BayPiggies and Silicon Valley Code Camp (which is a post for the near future). Both of these have kept me away from my blog. Let me make it up to you with a solution to project Euler problem #16.

The challenge is:

2^15 = 32768 and the sum of its digits is 3 + 2 + 7 + 6 + 8 = 26.
What is the sum of the digits of the number 21000?

`#!/usr/bin/python print sum([int(i) for i in str(2 ** 1000)])`

For this solution, using a more functional approach definitely reduced the code base. But one thing I was a little surprised about is that having a list comprehension within the sum function is actually faster than a generator expression. Usually one hears how generator expressions are preferred over list comprehensions because they are more efficient with memory, among other reasons. However, it's actually faster to give sum a list. One quick caveat, this whole sum and list comprehension thing applies to Python 2. The same seems to be also be true for Python 3, at least from the interpreter:

`>>> import timeit>>> timeit.timeit("sum(int(x) for x in str(2 ** 1000))", number=1000)0.11109958100132644>>> timeit.timeit("sum([int(x) for x in str(2 ** 1000)])", number=1000)0.09597363900684286>>> timeit.timeit("sum(int(x) for x in str(2 ** 1000))", number=10000)1.051396899012616>>> timeit.timeit("sum([int(x) for x in str(2 ** 1000)])", number=10000)0.9054670640034601>>> timeit.timeit("sum(int(x) for x in str(2 ** 1000))", number=100000)10.498383879996254>>> timeit.timeit("sum([int(x) for x in str(2 ** 1000)])", number=100000)8.992312036993098`

`module Main where import Data.Char main :: IO ()main = print . sum . map digitToInt . show \$ 2 ^ 1000`

Maybe it's just me and my Haskell/Python-centric brain, but I think the algorithm is simple enough to easily see the similarities and differences between the two languages. If I wanted to write the Haskell code to better match the Python code (syntactic differences aside), it would look like this: (inside the Haskell interpreter)

`Prelude Data.Char> print . sum \$ [ digitToInt x | x <- show (2 ^ 1000)]`

Even though this code may be easier to read for a Python programmer, it's not “good” Haskell code. It'll get the job done, but the map is obfuscated by the list comprehension. We can also adjust the Python code to make it resemble Haskell by using map:

`print sum(map(int, str(2 ** 1000)))`

But that might get you “dinged” because some people think that using map is “too functional” or “not Pythonic”, even if the code might be faster. I don't subscribe to that line of thinking...but that's a discussion for another time.

Times:
python – list comprehension : .032s
python – map : .030s
haskell – list ( interpreted) : .155s
haskell – map (interpreted) : .155s
haskell – list (compiled) : .006s
haskell – map (compiled) : .006s

As always, questions, comments, and complaints are encouraged. I hope everyone will forgive me for not posting for so long... sometimes life happens.

## Project Euler: Problem 14

“The following iterative sequence is defined for the set of positive integers: n → n/2 (n is even) n → 3n + 1 (n is odd).  Using the rule above and starting with 13, we generate the following sequence: 13 → 40 → 20 → 10 → 5 → 16 → 8 → 4 → 2 → 1.  It can be seen that this sequence (starting at 13 and finishing at 1) contains 10 terms.  Although it has not been proved yet (Collatz Problem), it is thought that all starting numbers finish at 1.  Which starting number, under one million, produces the longest chain?  NOTE: Once the chain starts the terms are allowed to go above one million.”

Not many of you may be aware of this, but about a year ago I wrote up a blog post that discussed Collatz chains in Haskell.  You can find that post here: . Having some of the code already written made coming up with the solution easier.  However, just because I had one function doesn't mean I had the whole problem licked.  I still had a fair amount of work in front of me.  Below is my code from the first attempt at a solution:

`module Main where  import Data.List chain' :: Integer -> [Integer]chain' 1 = [1]chain' n    | n <= 0 = []    | even n = n : chain' (n `div` 2)    | odd n = n : chain' (n * 3 + 1)  main :: IO () main = do     let seqx = map chain' [3..1000000]     let lengthx = map length seqx     print . maximum \$ zip lengthx seqx`

This code appears to be logically correct but was incredibly slow - so slow that after over 2 minutes it still hadn’t completed.  I admit I can be a little impatient with these things from time to time, but in this case something was obviously wrong.

I devised two optimizations:

• Reverse the order of the list. I will be more likely to find the number with the longest chain near 1,000,000 than 3.
• Use odd numbers only. This is based on the fact that in the chain' function an odd number gets multiplied right off the bat, whereas an even number is instantly divided by 2, and also on the assumption that a higher number will be more likely to have a longer chain.  (I admit this was a complete experiment - I had no proof that it would work ahead of time, and knew it gave me the right answer only after the fact.)

The code then morphed into:

`module Main where  import Data.List chain' :: Integer -> [Integer]chain' 1 = [1]chain' n    | n <= 0 = []    | even n = n : chain' (n `div` 2)    | odd n = n : chain' (n * 3 + 1)  main :: IO () main = do     let seqx = map chain' [999999,999997..3]     let lengthx = map length seqx     print . maximum \$ zip lengthx seqx`

The problem I ran into with this code was that I received stack overflow errors; my list of tuples holding another long list of int’s was taking up to much memory.  I fixed this problem by computing the length of the list immediately after generating it.  The new code looked like this:

`import Data.List chain' :: Integer -> [Integer]chain' 1 = [1]chain' n    | n <= 0 = []    | even n = n : chain' (n `div` 2)    | odd n = n : chain' (n * 3 + 1)  main :: IO () main = do     let seqx = map (\x → (x, length \$ chain' x) [999999,999997..3]     print . maximum \$ seqx`

This got me a result within the one minute time frame, but it still wasn't the right answer.  Can you figure out why?  Using the great code Jedai posted in the comments of my Apache log post, I was able to get my answer and finally complete the problem:

`module Main where                                                                                 import Data.Tuple  import Data.List (sortBy)  import Data.Function (on)    chain' :: Integer -> [Integer]  chain' 1 = [1]  chain' n    | n <= 0 = []    | even n = n : chain' (n `div` 2)    | odd n = n : chain' (n * 3 + 1)    main :: IO ()  main = do      let seqx = map (\x -> (x, length \$ chain' x)) [999999,999997..3]      print . fst . head \$ sortBy (flip compare `on` snd) seqx`

After figuring that out, getting the python answer was a breeze:

`#!/usr/bin/python"""Python solution for Project Euler problem #14.""" from itertools import imap def sequence(number):    t_num = number    count = 1     while(t_num > 1):        if t_num % 2 == 0:            t_num /= 2        else:            t_num = (t_num * 3) + 1         count += 1     return (count, number) if __name__ == "__main__":  print max(imap(sequence, xrange(999999,3,-2)))`

Here are the speed numbers:
Python : 18.537s

I think the use of recursion in my Haskell code is affecting its speed of computation.  As I learned from problem 12, I can use the State Monad again to speed things up.  But I also learned from the comments of problem 12 that some people were able to substitute a scan or fold in the State Monad’s place.  So I decided to shoot for one more solution.  After studying up on scan and fold, and finding that neither was really what I wanted, I found iterate. Using iterate I was able to change the program to this:

`module Main where  import Data.Tuple import Data.List (sortBy, iterate) import Data.Function (on)  chain' :: Integer -> Int chain' n       | n < 1 = 0     | otherwise = 1 + (length \$ (takeWhile ( > 1) \$ iterate (\x -> if even x then x `div` 2 else x * 3 + 1) n))  main :: IO () main = do     let seqx = map (\x -> (x, chain' x)) [999999,999997..3]     print . fst . head \$ sortBy (flip compare `on` snd) seqx`

The new chain' function doesn't read as cleanly as the old one, but it does remove the recursion I was talking about earlier.  The computer gods rewarded my efforts by reducing the run times to these:

From 14.758 to 10.933 - almost 4 seconds taken off the clock!  I think a speed up like that calls for some celebrating.  Which is exactly what I'm going to do before I start on problem 15.

## Project Euler: Problem 13

Problem thirteen from Project Euler is one of those problems that's so simple, I don't understand why it's in the double digits section. The problem reads: “Work out the first ten digits of the sum of the following one-hundred 50-digit numbers.”
It then proceeds to list 100 long numbers. I'm not going to paste them here because they are in the code solutions below and I don't want to clog up the “tubez” with more redundant information than I'm about to.

Enough of my jibber-jabber. Here is my Haskell solution first (trying to change things up here):

`module Main where main :: IO()main = do    print . take 10 . show \$ sum big_number    where big_number = [ 37107287533902102798797998220837590246510135740250                       , 46376937677490009712648124896970078050417018260538                       , 74324986199524741059474233309513058123726617309629                       , 91942213363574161572522430563301811072406154908250                       , 23067588207539346171171980310421047513778063246676                       , 89261670696623633820136378418383684178734361726757                       , 28112879812849979408065481931592621691275889832738                       , 44274228917432520321923589422876796487670272189318                       , 47451445736001306439091167216856844588711603153276                       , 70386486105843025439939619828917593665686757934951                       , 62176457141856560629502157223196586755079324193331                       , 64906352462741904929101432445813822663347944758178                       , 92575867718337217661963751590579239728245598838407                       , 58203565325359399008402633568948830189458628227828                       , 80181199384826282014278194139940567587151170094390                       , 35398664372827112653829987240784473053190104293586                       , 86515506006295864861532075273371959191420517255829                       , 71693888707715466499115593487603532921714970056938                       , 54370070576826684624621495650076471787294438377604                       , 53282654108756828443191190634694037855217779295145                       , 36123272525000296071075082563815656710885258350721                       , 45876576172410976447339110607218265236877223636045                       , 17423706905851860660448207621209813287860733969412                       , 81142660418086830619328460811191061556940512689692                       , 51934325451728388641918047049293215058642563049483                       , 62467221648435076201727918039944693004732956340691                       , 15732444386908125794514089057706229429197107928209                       , 55037687525678773091862540744969844508330393682126                       , 18336384825330154686196124348767681297534375946515                       , 80386287592878490201521685554828717201219257766954                       , 78182833757993103614740356856449095527097864797581                       , 16726320100436897842553539920931837441497806860984                       , 48403098129077791799088218795327364475675590848030                       , 87086987551392711854517078544161852424320693150332                       , 59959406895756536782107074926966537676326235447210                       , 69793950679652694742597709739166693763042633987085                       , 41052684708299085211399427365734116182760315001271                       , 65378607361501080857009149939512557028198746004375                       , 35829035317434717326932123578154982629742552737307                       , 94953759765105305946966067683156574377167401875275                       , 88902802571733229619176668713819931811048770190271                       , 25267680276078003013678680992525463401061632866526                       , 36270218540497705585629946580636237993140746255962                       , 24074486908231174977792365466257246923322810917141                       , 91430288197103288597806669760892938638285025333403                       , 34413065578016127815921815005561868836468420090470                       , 23053081172816430487623791969842487255036638784583                       , 11487696932154902810424020138335124462181441773470                       , 63783299490636259666498587618221225225512486764533                       , 67720186971698544312419572409913959008952310058822                       , 95548255300263520781532296796249481641953868218774                       , 76085327132285723110424803456124867697064507995236                       , 37774242535411291684276865538926205024910326572967                       , 23701913275725675285653248258265463092207058596522                       , 29798860272258331913126375147341994889534765745501                       , 18495701454879288984856827726077713721403798879715                       , 38298203783031473527721580348144513491373226651381                       , 34829543829199918180278916522431027392251122869539                       , 40957953066405232632538044100059654939159879593635                       , 29746152185502371307642255121183693803580388584903                       , 41698116222072977186158236678424689157993532961922                       , 62467957194401269043877107275048102390895523597457                       , 23189706772547915061505504953922979530901129967519                       , 86188088225875314529584099251203829009407770775672                       , 11306739708304724483816533873502340845647058077308                       , 82959174767140363198008187129011875491310547126581                       , 97623331044818386269515456334926366572897563400500                       , 42846280183517070527831839425882145521227251250327                       , 55121603546981200581762165212827652751691296897789                       , 32238195734329339946437501907836945765883352399886                       , 75506164965184775180738168837861091527357929701337                       , 62177842752192623401942399639168044983993173312731                       , 32924185707147349566916674687634660915035914677504                       , 99518671430235219628894890102423325116913619626622                       , 73267460800591547471830798392868535206946944540724                       , 76841822524674417161514036427982273348055556214818                       , 97142617910342598647204516893989422179826088076852                       , 87783646182799346313767754307809363333018982642090                       , 10848802521674670883215120185883543223812876952786                       , 71329612474782464538636993009049310363619763878039                       , 62184073572399794223406235393808339651327408011116                       , 66627891981488087797941876876144230030984490851411                       , 60661826293682836764744779239180335110989069790714                       , 85786944089552990653640447425576083659976645795096                       , 66024396409905389607120198219976047599490197230297                       , 64913982680032973156037120041377903785566085089252                       , 16730939319872750275468906903707539413042652315011                       , 94809377245048795150954100921645863754710598436791                       , 78639167021187492431995700641917969777599028300699                       , 15368713711936614952811305876380278410754449733078                       , 40789923115535562561142322423255033685442488917353                       , 44889911501440648020369068063960672322193204149535                       , 41503128880339536053299340368006977710650566631954                       , 81234880673210146739058568557934581403627822703280                       , 82616570773948327592232845941706525094512325230608                       , 22918802058777319719839450180888072429661980811197                       , 77158542502016545090413245809786882778948721859617                       , 72107838435069186155435662884062257473692284509516                       , 20849603980134001723930671666823555245252804609722                       , 53503534226472524250874054075591789781264330331690]`

followed by my Python solution:

`#!/usr/bin/python"""code solution for project euler's problem #13 in python."""from __future__ import print_function def print_10(number):    print(str(number)[0:10]) if __name__ == "__main__":     big_number = [ 37107287533902102798797998220837590246510135740250,                   46376937677490009712648124896970078050417018260538,                   74324986199524741059474233309513058123726617309629,                   91942213363574161572522430563301811072406154908250,                   23067588207539346171171980310421047513778063246676,                   89261670696623633820136378418383684178734361726757,                   28112879812849979408065481931592621691275889832738,                   44274228917432520321923589422876796487670272189318,                   47451445736001306439091167216856844588711603153276,                   70386486105843025439939619828917593665686757934951,                   62176457141856560629502157223196586755079324193331,                   64906352462741904929101432445813822663347944758178,                   92575867718337217661963751590579239728245598838407,                   58203565325359399008402633568948830189458628227828,                   80181199384826282014278194139940567587151170094390,                   35398664372827112653829987240784473053190104293586,                   86515506006295864861532075273371959191420517255829,                   71693888707715466499115593487603532921714970056938,                   54370070576826684624621495650076471787294438377604,                   53282654108756828443191190634694037855217779295145,                   36123272525000296071075082563815656710885258350721,                   45876576172410976447339110607218265236877223636045,                   17423706905851860660448207621209813287860733969412,                   81142660418086830619328460811191061556940512689692,                   51934325451728388641918047049293215058642563049483,                   62467221648435076201727918039944693004732956340691,                   15732444386908125794514089057706229429197107928209,                   55037687525678773091862540744969844508330393682126,                   18336384825330154686196124348767681297534375946515,                   80386287592878490201521685554828717201219257766954,                   78182833757993103614740356856449095527097864797581,                   16726320100436897842553539920931837441497806860984,                   48403098129077791799088218795327364475675590848030,                   87086987551392711854517078544161852424320693150332,                   59959406895756536782107074926966537676326235447210,                   69793950679652694742597709739166693763042633987085,                   41052684708299085211399427365734116182760315001271,                   65378607361501080857009149939512557028198746004375,                   35829035317434717326932123578154982629742552737307,                   94953759765105305946966067683156574377167401875275,                   88902802571733229619176668713819931811048770190271,                   25267680276078003013678680992525463401061632866526,                   36270218540497705585629946580636237993140746255962,                   24074486908231174977792365466257246923322810917141,                   91430288197103288597806669760892938638285025333403,                   34413065578016127815921815005561868836468420090470,                   23053081172816430487623791969842487255036638784583,                   11487696932154902810424020138335124462181441773470,                   63783299490636259666498587618221225225512486764533,                   67720186971698544312419572409913959008952310058822,                   95548255300263520781532296796249481641953868218774,                   76085327132285723110424803456124867697064507995236,                   37774242535411291684276865538926205024910326572967,                   23701913275725675285653248258265463092207058596522,                   29798860272258331913126375147341994889534765745501,                   18495701454879288984856827726077713721403798879715,                   38298203783031473527721580348144513491373226651381,                   34829543829199918180278916522431027392251122869539,                   40957953066405232632538044100059654939159879593635,                   29746152185502371307642255121183693803580388584903,                   41698116222072977186158236678424689157993532961922,                   62467957194401269043877107275048102390895523597457,                   23189706772547915061505504953922979530901129967519,                   86188088225875314529584099251203829009407770775672,                   11306739708304724483816533873502340845647058077308,                   82959174767140363198008187129011875491310547126581,                   97623331044818386269515456334926366572897563400500,                   42846280183517070527831839425882145521227251250327,                   55121603546981200581762165212827652751691296897789,                   32238195734329339946437501907836945765883352399886,                   75506164965184775180738168837861091527357929701337,                   62177842752192623401942399639168044983993173312731,                   32924185707147349566916674687634660915035914677504,                   99518671430235219628894890102423325116913619626622,                   73267460800591547471830798392868535206946944540724,                   76841822524674417161514036427982273348055556214818,                   97142617910342598647204516893989422179826088076852,                   87783646182799346313767754307809363333018982642090,                   10848802521674670883215120185883543223812876952786,                   71329612474782464538636993009049310363619763878039,                   62184073572399794223406235393808339651327408011116,                   66627891981488087797941876876144230030984490851411,                   60661826293682836764744779239180335110989069790714,                   85786944089552990653640447425576083659976645795096,                   66024396409905389607120198219976047599490197230297,                   64913982680032973156037120041377903785566085089252,                   16730939319872750275468906903707539413042652315011,                   94809377245048795150954100921645863754710598436791,                   78639167021187492431995700641917969777599028300699,                   15368713711936614952811305876380278410754449733078,                   40789923115535562561142322423255033685442488917353,                   44889911501440648020369068063960672322193204149535,                   41503128880339536053299340368006977710650566631954,                   81234880673210146739058568557934581403627822703280,                   82616570773948327592232845941706525094512325230608,                   22918802058777319719839450180888072429661980811197,                   77158542502016545090413245809786882778948721859617,                   72107838435069186155435662884062257473692284509516,                   20849603980134001723930671666823555245252804609722,                   53503534226472524250874054075591789781264330331690]     print_10(sum(big_number))`

and to continue adding in the spice, I have included a solution in Scala:

`import BigInt._ object problem_13 {    def main (args : Array[String]){        val big_number = List("37107287533902102798797998220837590246510135740250",                              "46376937677490009712648124896970078050417018260538",                              "74324986199524741059474233309513058123726617309629",                              "91942213363574161572522430563301811072406154908250",                              "23067588207539346171171980310421047513778063246676",                              "89261670696623633820136378418383684178734361726757",                              "28112879812849979408065481931592621691275889832738",                              "44274228917432520321923589422876796487670272189318",                              "47451445736001306439091167216856844588711603153276",                              "70386486105843025439939619828917593665686757934951",                              "62176457141856560629502157223196586755079324193331",                              "64906352462741904929101432445813822663347944758178",                              "92575867718337217661963751590579239728245598838407",                              "58203565325359399008402633568948830189458628227828",                              "80181199384826282014278194139940567587151170094390",                              "35398664372827112653829987240784473053190104293586",                              "86515506006295864861532075273371959191420517255829",                              "71693888707715466499115593487603532921714970056938",                              "54370070576826684624621495650076471787294438377604",                              "53282654108756828443191190634694037855217779295145",                              "36123272525000296071075082563815656710885258350721",                              "45876576172410976447339110607218265236877223636045",                              "17423706905851860660448207621209813287860733969412",                              "81142660418086830619328460811191061556940512689692",                              "51934325451728388641918047049293215058642563049483",                              "62467221648435076201727918039944693004732956340691",                              "15732444386908125794514089057706229429197107928209",                              "55037687525678773091862540744969844508330393682126",                              "18336384825330154686196124348767681297534375946515",                              "80386287592878490201521685554828717201219257766954",                              "78182833757993103614740356856449095527097864797581",                              "16726320100436897842553539920931837441497806860984",                              "48403098129077791799088218795327364475675590848030",                              "87086987551392711854517078544161852424320693150332",                              "59959406895756536782107074926966537676326235447210",                              "69793950679652694742597709739166693763042633987085",                              "41052684708299085211399427365734116182760315001271",                              "65378607361501080857009149939512557028198746004375",                              "35829035317434717326932123578154982629742552737307",                              "94953759765105305946966067683156574377167401875275",                              "88902802571733229619176668713819931811048770190271",                              "25267680276078003013678680992525463401061632866526",                              "36270218540497705585629946580636237993140746255962",                              "24074486908231174977792365466257246923322810917141",                              "91430288197103288597806669760892938638285025333403",                              "34413065578016127815921815005561868836468420090470",                              "23053081172816430487623791969842487255036638784583",                              "11487696932154902810424020138335124462181441773470",                              "63783299490636259666498587618221225225512486764533",                              "67720186971698544312419572409913959008952310058822",                              "95548255300263520781532296796249481641953868218774",                              "76085327132285723110424803456124867697064507995236",                              "37774242535411291684276865538926205024910326572967",                              "23701913275725675285653248258265463092207058596522",                              "29798860272258331913126375147341994889534765745501",                              "18495701454879288984856827726077713721403798879715",                              "38298203783031473527721580348144513491373226651381",                              "34829543829199918180278916522431027392251122869539",                              "40957953066405232632538044100059654939159879593635",                              "29746152185502371307642255121183693803580388584903",                              "41698116222072977186158236678424689157993532961922",                              "62467957194401269043877107275048102390895523597457",                              "23189706772547915061505504953922979530901129967519",                              "86188088225875314529584099251203829009407770775672",                              "11306739708304724483816533873502340845647058077308",                              "82959174767140363198008187129011875491310547126581",                              "97623331044818386269515456334926366572897563400500",                              "42846280183517070527831839425882145521227251250327",                              "55121603546981200581762165212827652751691296897789",                              "32238195734329339946437501907836945765883352399886",                              "75506164965184775180738168837861091527357929701337",                              "62177842752192623401942399639168044983993173312731",                              "32924185707147349566916674687634660915035914677504",                              "99518671430235219628894890102423325116913619626622",                              "73267460800591547471830798392868535206946944540724",                              "76841822524674417161514036427982273348055556214818",                              "97142617910342598647204516893989422179826088076852",                              "87783646182799346313767754307809363333018982642090",                              "10848802521674670883215120185883543223812876952786",                              "71329612474782464538636993009049310363619763878039",                              "62184073572399794223406235393808339651327408011116",                              "66627891981488087797941876876144230030984490851411",                              "60661826293682836764744779239180335110989069790714",                              "85786944089552990653640447425576083659976645795096",                              "66024396409905389607120198219976047599490197230297",                              "64913982680032973156037120041377903785566085089252",                              "16730939319872750275468906903707539413042652315011",                              "94809377245048795150954100921645863754710598436791",                              "78639167021187492431995700641917969777599028300699",                              "15368713711936614952811305876380278410754449733078",                              "40789923115535562561142322423255033685442488917353",                              "44889911501440648020369068063960672322193204149535",                              "41503128880339536053299340368006977710650566631954",                              "81234880673210146739058568557934581403627822703280",                              "82616570773948327592232845941706525094512325230608",                              "22918802058777319719839450180888072429661980811197",                              "77158542502016545090413245809786882778948721859617",                              "72107838435069186155435662884062257473692284509516",                              "20849603980134001723930671666823555245252804609722",                              "53503534226472524250874054075591789781264330331690") map {BigInt(_)}        val sums = big_number sum        val su = sums toString        val su10 = su take 10        println(su10)    }}`

Some of you may be wondering, “Why a Scala solution?” To which I respond, “Why not?” Because that's a little short, I'll add that it has something to do with Scala starting to gain traction in the industry and me seeing if I would like to get paid to program in it.

The solution, in all three languages, is pretty simple. The recipe essentially says, “Put all numbers into a list. Get the sum of that list, turn that number into a string, and get the first 10 characters of that string.”

Times: