Fibonacci numbers

Mathematica
Note, that this implementation exists. Algorithm is:

Fibonacci[n_] := Round[GoldenRatio^n/Sqrt[5]]

Be aware, that this formula:

can not be trivially applied in other languages.

Java
In Java, we have arbitrarily large integers and decimals, but prebuilt classes lack the functionality (it's a shame). For example we can not easily take root of 5. To do this, we would need to use a library like JScience or write Newton approximation method (what can be quite error prone process).


C#
In C#, there is no arbitrarily large decimals. It does have class decimal (with 28-29 significant digits), but assuming that Math class supports it, is just asking too much (it's a shame). But thumbs up, for it at least has BigInteger.

Euler Problem 48 solution

Time (s): ~0.034

package margusmartseppcode.From_40_to_49;

public class Problem_48 {
 public static void main(String[] args) {
  long result = 0, d10 = 10000000000L;
  for (long u = 1, tmp = u; u <= 1000; result += tmp, ++u, tmp = u)
   for (long v = 1; v < u; ++v)
    tmp = (tmp * u) % d10;

  System.out.println(result % d10);
 }
}

Time (s): ~0.224

package margusmartseppcode.From_40_to_49;

import java.math.BigInteger;

public class Problem_48 {
 // Note: i = 2 !!!
 public static void main(String[] args) {
  BigInteger num = BigInteger.ONE;
  for (int i = 2; i < 1000; i++)
   num = num.add(BigInteger.valueOf(i).pow(i));
  String result = num.toString();
  System.out.println(result.substring(result.length() - 10));
 }
}

Euler Problem 20 solution

Time (s): ~0.001

package margusmartseppcode.From_20_to_29;

import java.math.BigInteger;

public class Problem_20 {
 static final int maxSize = 101;
 static BigInteger f[] = new BigInteger[maxSize];
 static {
  f[0] = BigInteger.ONE;
  for (int i = 1; i < maxSize; i++)
   f[i] = f[i - 1].multiply(BigInteger.valueOf(i));
 }

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

  for (char c : f[100].toString().toCharArray())
   sum += Character.getNumericValue(c);

  System.out.println(sum);
 }
}

Euler Problem 16 solution

Time (s): ~0.003

package margusmartseppcode.From_10_to_19;

import java.math.BigInteger;

public class Problem_16 {

 public static void main(String[] args) {
  int sum = 0;
  for (char c : BigInteger.valueOf(2L).pow(1000).toString().toCharArray())
   sum += c - '0';
  System.out.println(sum);
 }
}

Euler Problem 15 solution

Time (s): ~0.001

package margusmartseppcode.From_10_to_19;

import java.math.BigInteger;

public class Problem_15 {
 static final int maxSize = 42;
 static BigInteger f[] = new BigInteger[maxSize];
 static {
  f[0] = BigInteger.ONE;
  for (int i = 1; i < maxSize; i++)
   f[i] = f[i - 1].multiply(BigInteger.valueOf(i));
 }

 public static void main(String[] args) {
  // s=x=y
  // !(x+y)/!x*!y
  int s = 20;
  System.out.println(f[s + s].divide((f[s].multiply(f[s]))));
 }
}

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));
 }
}