Euler Problem 42 solution

Time (s): ~0.067

package margusmartseppcode.From_40_to_49;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.HashMap;
import java.util.Scanner;
import java.util.Map;

public class Problem_42 {
 static int sumStringChars(String s) {
  if (s == null)
   return 0;
  int n = s.length(), sum = 0;
  for (int i = 0; i < n; i++)
   sum += s.charAt(i) - '@';
  return sum;
 }

 public static void main(String[] args) throws FileNotFoundException {
  Map<Integer, Integer> map = new HashMap<Integer, Integer>();
  String raw = new Scanner(new File("words.txt")).next();
  String str[] = raw.substring(1, raw.length() - 1).split("\",\"");
  int count = 0;

  for (String s : str) {
   int tmp = sumStringChars(s);
   map.put(tmp, map.containsKey(tmp) ? map.get(tmp) + 1 : 1);
  }

  for (Integer i : map.keySet())
   if ((((Math.sqrt(1 + 8 * i) - 1) / 2) % 1 == 0))
    count += map.get(i);

  System.out.println(count);
 }
}

Euler Problem 40 solution

Time (s): ~0.008

package margusmartseppcode.From_40_to_49;

public class Problem_40 {
 public static void main(String[] args) {
  int size = 100000, result = 1;
  StringBuilder sb = new StringBuilder(size + 200);

  for (int i = 1; sb.length() <= 100000; i++)
   sb.append(i);

  for (int count = 1; count <= size; count *= 10)
   result *= Character.getNumericValue(sb.charAt(count - 1));

  System.out.println(result);
 }
}

Euler Problem 22 solution

Time (s): ~0.096

package margusmartseppcode.From_20_to_29;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Arrays;
import java.util.Scanner;

public class Problem_22 {
 public static void main(String[] args) throws FileNotFoundException {
  String raw = new Scanner(new File("names.txt")).next();
  String str[] = raw.substring(1, raw.length() - 1).split("\",\"");
  long ls = 0, ts = 0;
  Arrays.sort(str);

  for (int i = 0; i < str.length; i++, ls = 0) {
   for (char c : str[i].toCharArray())
    ls += c - '@';

   ts += ls * (i + 1);
  }
  System.out.println(ts);
 }
}

Euler Problem 17 solution

Time (s): ~0.002

package margusmartseppcode.From_10_to_19;

public class Problem_17 {
 static int hundred = "hundred".length();
 static int hundredand = "hundredand".length();
 static int onethousand = "onethousand".length();
 static int lens[] = new int[100];
 static {
  String tmp[] = ("| one two three four five six seven eight nine "
    + "| eleven twelve thirteen fourteen fifteen sixteen "
    + "seventeen eighteen nineteen | ten twenty thirty forty "
    + "fifty sixty seventy eighty ninety").split(" ");
  for (int i = 1; i < 10; i++) {
   lens[i] = tmp[i].length();
   lens[i + 10] = tmp[i + 10].length();
   lens[i * 10] = tmp[i + 20].length();
  }
  for (int i = 2; i < 10; i++)
   for (int j = 1; j < 10; j++)
    lens[i * 10 + j] = lens[i * 10] + lens[j];
 }

 public static void main(String[] args) {
  int sum = 0, hundredsum = 0;

  for (int i = 1; i < lens.length; i++)
   hundredsum += lens[i];

  sum = hundredsum;
  for (int i = 1; i < 10; i++)
   sum += lens[i] + hundred + (lens[i] + hundredand) * 99
     + hundredsum;

  sum += onethousand;
  System.out.println(sum);
 }
}

Euler Problem 13 solution

Time (s): ~0.010

package margusmartseppcode.From_10_to_19;

import java.math.BigInteger;

public class Problem_13 {
 static String str[] = {
   "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" };

 public static void main(String[] args) {
  BigInteger tmp = BigInteger.ZERO;
  for (String s : str)
   tmp=tmp.add(new BigInteger(s));
  System.out.println(tmp.toString().substring(0, 10));
 }
}

Euler Problem 8 solution

Time (s): ~0.001

package margusmartseppcode.From_1_to_9;

public class Problem_8 {
 public static void main(String[] args) {
  char[] nr = ("7316717653133062491922511967442657474235534919493"
    + "496983520312774506326239578318016984801869478851843"
    + "858615607891129494954595017379583319528532088055111"
    + "254069874715852386305071569329096329522744304355766"
    + "896648950445244523161731856403098711121722383113622"
    + "298934233803081353362766142828064444866452387493035"
    + "890729629049156044077239071381051585930796086670172"
    + "427121883998797908792274921901699720888093776657273"
    + "330010533678812202354218097512545405947522435258490"
    + "771167055601360483958644670632441572215539753697817"
    + "977846174064955149290862569321978468622482839722413"
    + "756570560574902614079729686524145351004748216637048"
    + "440319989000889524345065854122758866688116427171479"
    + "924442928230863465674813919123162824586178664583591"
    + "245665294765456828489128831426076900422421902267105"
    + "562632111110937054421750694165896040807198403850962"
    + "455444362981230987879927244284909188845801561660979"
    + "191338754992005240636899125607176060588611646710940"
    + "507754100225698315520005593572972571636269561882670"
    + "428252483600823257530420752963450").toCharArray();
  int tmp = 0, max = 0;

  for (int i = 4; i < nr.length; i++, tmp = 1) {
   for (int j = -4; j <= 0; j++)
    tmp *= (nr[i + j] - '0');

   if (tmp > max)
    max = tmp;
  }
  System.out.println(max);
 }
}