Title: Project Euler problem 9 and 10, with Haskell
Date: 2015-11-07T00:00:00
Tags: Project Euler, Haskell

Problem 11

Not the cleanest implementation of this program however, it does work.

ProjectEuler11.hs

main :: IO ()
main = do
    putStrLn "ProjectEuler.net"
    putStrLn "Problem11 - Largest product in a grid"
    print (maximum problem11)
    
problem11 = [(maximum horizProd), (maximum vertiProd), (maximum diagFProd), (maximum diagBProd)]


horizProd = [product (take 4 (drop y (grid!!x))) | x <- [0..19], y <- [0..16]]
vertiProd = [grid!!x!!y * grid!!(x+1)!!y * grid!!(x+2)!!y * grid!!(x+3)!!y | x <- [1..16], y <- [0..19]]
diagFProd = [grid!!x!!y * grid!!(x+1)!!(y+1) * grid!!(x+2)!!(y+2) * grid!!(x+3)!!(y+3) | x <- [1..16], y <- [0..16]]
diagBProd = [grid!!x!!(y+3) * grid!!(x+1)!!(y+2) * grid!!(x+2)!!(y+1) * grid!!(x+3)!!y | x <- [1..16], y <- [0..16]]
grid = [[08, 02, 22, 97, 38, 15, 00, 40, 00, 75, 04, 05, 07, 78, 52, 12, 50, 77, 91, 08],
        [49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40, 98, 43, 69, 48, 04, 56, 62, 00],
        [81, 49, 31, 73, 55, 79, 14, 29, 93, 71, 40, 67, 53, 88, 30, 03, 49, 13, 36, 65],
        [52, 70, 95, 23, 04, 60, 11, 42, 69, 24, 68, 56, 01, 32, 56, 71, 37, 02, 36, 91],
        [22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28, 66, 33, 13, 80],
        [24, 47, 32, 60, 99, 03, 45, 02, 44, 75, 33, 53, 78, 36, 84, 20, 35, 17, 12, 50],
        [32, 98, 81, 28, 64, 23, 67, 10, 26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70],
        [67, 26, 20, 68, 02, 62, 12, 20, 95, 63, 94, 39, 63, 08, 40, 91, 66, 49, 94, 21],
        [24, 55, 58, 05, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88, 34, 89, 63, 72],
        [21, 36, 23, 09, 75, 00, 76, 44, 20, 45, 35, 14, 00, 61, 33, 97, 34, 31, 33, 95],
        [78, 17, 53, 28, 22, 75, 31, 67, 15, 94, 03, 80, 04, 62, 16, 14, 09, 53, 56, 92],
        [16, 39, 05, 42, 96, 35, 31, 47, 55, 58, 88, 24, 00, 17, 54, 24, 36, 29, 85, 57],
        [86, 56, 00, 48, 35, 71, 89, 07, 05, 44, 44, 37, 44, 60, 21, 58, 51, 54, 17, 58],
        [19, 80, 81, 68, 05, 94, 47, 69, 28, 73, 92, 13, 86, 52, 17, 77, 04, 89, 55, 40],
        [04, 52, 08, 83, 97, 35, 99, 16, 07, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66],
        [88, 36, 68, 87, 57, 62, 20, 72, 03, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69],
        [04, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18, 08, 46, 29, 32, 40, 62, 76, 36],
        [20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69, 82, 67, 59, 85, 74, 04, 36, 16],
        [20, 73, 35, 29, 78, 31, 90, 01, 74, 31, 49, 71, 48, 86, 81, 16, 23, 57, 05, 54],
        [01, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 01, 89, 19, 67, 48]]

Problem 12

Another really straight forward problem using infinite lists.

ProjectEuler12.hs

main :: IO ()
main = do
    putStrLn "ProjectEuler.net"
    putStrLn "Problem12 - Highly divisible triangular number"
    print problem13
    

problem13 = sum nums

nums = [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]