WeixiangYan/CodeTransOcean huggingface dataset:
Task: Padovan sequence







Python: from math import floor
from collections import deque
from typing import Dict, Generator


def padovan_r() -> Generator[int, None, None]:
    last = deque([1, 1, 1], 4)
    while True:
        last.append(last[-2] + last[-3])
        yield last.popleft()

_p, _s = 1.324717957244746025960908854, 1.0453567932525329623

def padovan_f(n: int) -> int:
    return floor(_p**(n-1) / _s + .5)

def padovan_l(start: str='A',
             rules: Dict[str, str]=dict(A='B', B='C', C='AB')
             ) -> Generator[str, None, None]:
    axiom = start
    while True:
        yield axiom
        axiom = ''.join(rules[ch] for ch in axiom)


if __name__ == "__main__":
    from itertools import islice

    print("The first twenty terms of the sequence.")
    print(str([padovan_f(n) for n in range(20)])[1:-1])

    r_generator = padovan_r()
    if all(next(r_generator) == padovan_f(n) for n in range(64)):
        print("\nThe recurrence and floor based algorithms match to n=63 .")
    else:
        print("\nThe recurrence and floor based algorithms DIFFER!")

    print("\nThe first 10 L-system string-lengths and strings")
    l_generator = padovan_l(start='A', rules=dict(A='B', B='C', C='AB'))
    print('\n'.join(f"  {len(string):3} {repr(string)}"
                    for string in islice(l_generator, 10)))

    r_generator = padovan_r()
    l_generator = padovan_l(start='A', rules=dict(A='B', B='C', C='AB'))
    if all(len(next(l_generator)) == padovan_f(n) == next(r_generator)
           for n in range(32)):
        print("\nThe L-system, recurrence and floor based algorithms match to n=31 .")
    else:
        print("\nThe L-system, recurrence and floor based algorithms DIFFER!")
Task: Monads_Maybe monad







Python: 
from __future__ import annotations

from typing import Any
from typing import Callable
from typing import Generic
from typing import Optional
from typing import TypeVar
from typing import Union


T = TypeVar("T")


class Maybe(Generic[T]):
    def __init__(self, value: Union[Optional[T], Maybe[T]] = None):
        if isinstance(value, Maybe):
            self.value: Optional[T] = value.value
        else:
            self.value = value

    def __rshift__(self, func: Callable[[Optional[T]], Maybe[Any]]):
        return self.bind(func)

    def bind(self, func: Callable[[Optional[T]], Maybe[Any]]) -> Maybe[Any]:
        return func(self.value)

    def __str__(self):
        return f"{self.__class__.__name__}({self.value!r})"


def plus_one(value: Optional[int]) -> Maybe[int]:
    if value is not None:
        return Maybe[int](value + 1)
    return Maybe[int](None)


def currency(value: Optional[int]) -> Maybe[str]:
    if value is not None:
        return Maybe[str](f"${value}.00")
    return Maybe[str](None)


if __name__ == "__main__":
    test_cases = [1, 99, None, 4]

    for case in test_cases:
        m_int = Maybe[int](case)
        result = m_int >> plus_one >> currency
        
        
        print(f"{str(case):<4} -> {result}")
Task: Monads_List monad







Python: 
from __future__ import annotations
from itertools import chain

from typing import Any
from typing import Callable
from typing import Iterable
from typing import List
from typing import TypeVar


T = TypeVar("T")


class MList(List[T]):
    @classmethod
    def unit(cls, value: Iterable[T]) -> MList[T]:
        return cls(value)

    def bind(self, func: Callable[[T], MList[Any]]) -> MList[Any]:
        return MList(chain.from_iterable(map(func, self)))

    def __rshift__(self, func: Callable[[T], MList[Any]]) -> MList[Any]:
        return self.bind(func)


if __name__ == "__main__":
    
    print(
        MList([1, 99, 4])
        .bind(lambda val: MList([val + 1]))
        .bind(lambda val: MList([f"${val}.00"]))
    )

    
    print(
        MList([1, 99, 4])
        >> (lambda val: MList([val + 1]))
        >> (lambda val: MList([f"${val}.00"]))
    )

    
    print(
        MList(range(1, 6)).bind(
            lambda x: MList(range(6, 11)).bind(lambda y: MList([(x, y)]))
        )
    )

    
    print(
        MList(range(1, 26)).bind(
            lambda x: MList(range(x + 1, 26)).bind(
                lambda y: MList(range(y + 1, 26)).bind(
                    lambda z: MList([(x, y, z)])
                    if x * x + y * y == z * z
                    else MList([])
                )
            )
        )
    )
Task: Textonyms







Python: from collections import defaultdict
import urllib.request

CH2NUM = {ch: str(num) for num, chars in enumerate('abc def ghi jkl mno pqrs tuv wxyz'.split(), 2) for ch in chars}
URL = 'http://www.puzzlers.org/pub/wordlists/unixdict.txt'


def getwords(url):
 return urllib.request.urlopen(url).read().decode("utf-8").lower().split()

def mapnum2words(words):
    number2words = defaultdict(list)
    reject = 0
    for word in words:
        try:
            number2words[''.join(CH2NUM[ch] for ch in word)].append(word)
        except KeyError:
            
            reject += 1
    return dict(number2words), reject

def interactiveconversions():
    global inp, ch, num
    while True:
        inp = input("\nType a number or a word to get the translation and textonyms: ").strip().lower()
        if inp:
            if all(ch in '23456789' for ch in inp):
                if inp in num2words:
                    print("  Number {0} has the following textonyms in the dictionary: {1}".format(inp, ', '.join(
                        num2words[inp])))
                else:
                    print("  Number {0} has no textonyms in the dictionary.".format(inp))
            elif all(ch in CH2NUM for ch in inp):
                num = ''.join(CH2NUM[ch] for ch in inp)
                print("  Word {0} is{1} in the dictionary and is number {2} with textonyms: {3}".format(
                    inp, ('' if inp in wordset else "n't"), num, ', '.join(num2words[num])))
            else:
                print("  I don't understand %r" % inp)
        else:
            print("Thank you")
            break


if __name__ == '__main__':
    words = getwords(URL)
    print("Read %i words from %r" % (len(words), URL))
    wordset = set(words)
    num2words, reject = mapnum2words(words)
    morethan1word = sum(1 for w in num2words if len(num2words[w]) > 1)
    maxwordpernum = max(len(values) for values in num2words.values())
    print(.format(len(words) - reject, URL, len(num2words), morethan1word))

    print("\nThe numbers mapping to the most words map to %i words each:" % maxwordpernum)
    maxwpn = sorted((key, val) for key, val in num2words.items() if len(val) == maxwordpernum)
    for num, wrds in maxwpn:
        print("  %s maps to: %s" % (num, ', '.join(wrds)))

    interactiveconversions()
Task: Church numerals







Python: 

from itertools import repeat
from functools import reduce




def churchZero():
    
    return lambda f: identity


def churchSucc(cn):
    
    return lambda f: compose(f)(cn(f))


def churchAdd(m):
    
    return lambda n: lambda f: compose(m(f))(n(f))


def churchMult(m):
    
    return lambda n: compose(m)(n)


def churchExp(m):
    
    return lambda n: n(m)


def churchFromInt(n):
    
    return lambda f: (
        foldl
        (compose)
        (identity)
        (replicate(n)(f))
    )



def churchFromInt_(n):
    
    if 0 == n:
        return churchZero()
    else:
        return churchSucc(churchFromInt(n - 1))


def intFromChurch(cn):
    
    return cn(succ)(0)




def main():
    'Tests'

    cThree = churchFromInt(3)
    cFour = churchFromInt(4)

    print(list(map(intFromChurch, [
        churchAdd(cThree)(cFour),
        churchMult(cThree)(cFour),
        churchExp(cFour)(cThree),
        churchExp(cThree)(cFour),
    ])))





def compose(f):
    
    return lambda g: lambda x: g(f(x))



def foldl(f):
    
    def go(acc, xs):
        return reduce(lambda a, x: f(a)(x), xs, acc)
    return lambda acc: lambda xs: go(acc, xs)



def identity(x):
    
    return x



def replicate(n):
    
    return lambda x: repeat(x, n)



def succ(x):
    
    return 1 + x if isinstance(x, int) else (
        chr(1 + ord(x))
    )


if __name__ == '__main__':
    main()
Task: Reflection_List methods







Python: import inspect


class Super(object):
  def __init__(self, name):
    self.name = name
  
  def __str__(self):
    return "Super(%s)" % (self.name,)
  
  def doSup(self):
    return 'did super stuff'
  
  @classmethod
  def cls(cls):
    return 'cls method (in sup)'
  
  @classmethod
  def supCls(cls):
    return 'Super method'
  
  @staticmethod
  def supStatic():
    return 'static method'

class Other(object):
  def otherMethod(self):
    return 'other method'

class Sub(Other, Super):
  def __init__(self, name, *args):
    super(Sub, self).__init__(name);
    self.rest = args;
    self.methods = {}
  
  def __dir__(self):
    return list(set( \
        sum([dir(base) for base in type(self).__bases__], []) \
        + type(self).__dict__.keys() \
        + self.__dict__.keys() \
        + self.methods.keys() \
      ))
  
  def __getattr__(self, name):
    if name in self.methods:
      if callable(self.methods[name]) and self.methods[name].__code__.co_argcount > 0:
        if self.methods[name].__code__.co_varnames[0] == 'self':
          return self.methods[name].__get__(self, type(self))
        if self.methods[name].__code__.co_varnames[0] == 'cls':
          return self.methods[name].__get__(type(self), type)
      return self.methods[name]
    raise AttributeError("'%s' object has no attribute '%s'" % (type(self).__name__, name))
  
  def __str__(self):
    return "Sub(%s)" % self.name
  
  def doSub():
    return 'did sub stuff'
  
  @classmethod
  def cls(cls):
    return 'cls method (in Sub)'
  
  @classmethod
  def subCls(cls):
    return 'Sub method'
  
  @staticmethod
  def subStatic():
    return 'Sub method'

sup = Super('sup')
sub = Sub('sub', 0, 'I', 'two')
sub.methods['incr'] = lambda x: x+1
sub.methods['strs'] = lambda self, x: str(self) * x


[method for method in dir(sub) if callable(getattr(sub, method))]

[method for method in dir(sub) if callable(getattr(sub, method)) and hasattr(getattr(sub, method), '__self__') and getattr(sub, method).__self__ == sub]


[method for method in dir(sub) if callable(getattr(sub, method)) and hasattr(getattr(sub, method), '__self__') and getattr(sub, method).__self__ == type(sub)]


[method for method in dir(sub) if callable(getattr(sub, method)) and type(getattr(sub, method)) == type(lambda:nil)]



inspect.getmembers(sub, predicate=inspect.ismethod)

map(lambda t: t[0], inspect.getmembers(sub, predicate=inspect.ismethod))
Task: Topic variable







Python: >>> 3
3
>>> _*_, _**0.5
(9, 1.7320508075688772)
>>>
Task: Permutations_Rank of a permutation







Python: from math import factorial as fact
from random import randrange
from textwrap import wrap

def identity_perm(n): 
    return list(range(n))

def unranker1(n, r, pi):
    while n > 0:
        n1, (rdivn, rmodn) = n-1, divmod(r, n)
        pi[n1], pi[rmodn] = pi[rmodn], pi[n1]
        n = n1
        r = rdivn
    return pi

def init_pi1(n, pi): 
    pi1 = [-1] * n
    for i in range(n): 
        pi1[pi[i]] = i
    return pi1

def ranker1(n, pi, pi1):
    if n == 1: 
        return 0
    n1 = n-1
    s = pi[n1]
    pi[n1], pi[pi1[n1]] = pi[pi1[n1]], pi[n1]
    pi1[s], pi1[n1] = pi1[n1], pi1[s]
    return s + n * ranker1(n1, pi, pi1)

def unranker2(n, r, pi):
    while n > 0:
        n1 = n-1
        s, rmodf = divmod(r, fact(n1))
        pi[n1], pi[s] = pi[s], pi[n1]
        n = n1
        r = rmodf
    return pi

def ranker2(n, pi, pi1):
    if n == 1: 
        return 0
    n1 = n-1
    s = pi[n1]
    pi[n1], pi[pi1[n1]] = pi[pi1[n1]], pi[n1]
    pi1[s], pi1[n1] = pi1[n1], pi1[s]
    return s * fact(n1) + ranker2(n1, pi, pi1)

def get_random_ranks(permsize, samplesize):    
    perms = fact(permsize)
    ranks = set()
    while len(ranks) < samplesize:
        ranks |= set( randrange(perms) 
                      for r in range(samplesize - len(ranks)) )
    return ranks    

def test1(comment, unranker, ranker):    
    n, samplesize, n2 = 3, 4, 12
    print(comment)
    perms = []
    for r in range(fact(n)):
        pi = identity_perm(n)
        perm = unranker(n, r, pi)
        perms.append((r, perm))
    for r, pi in perms:
        pi1 = init_pi1(n, pi)
        print('  From rank %2i to %r back to %2i' % (r, pi, ranker(n, pi[:], pi1)))
    print('\n  %i random individual samples of %i items:' % (samplesize, n2))
    for r in get_random_ranks(n2, samplesize):
        pi = identity_perm(n2)
        print('    ' + ' '.join('%2i' % i for i in unranker(n2, r, pi)))
    print('')

def test2(comment, unranker):    
    samplesize, n2 = 4, 144
    print(comment)
    print('  %i random individual samples of %i items:' % (samplesize, n2))
    for r in get_random_ranks(n2, samplesize):
        pi = identity_perm(n2)
        print('    ' + '\n      '.join(wrap(repr(unranker(n2, r, pi)))))
    print('')

if __name__ == '__main__':
    test1('First ordering:', unranker1, ranker1)
    test1('Second ordering:', unranker2, ranker2)
    test2('First ordering, large number of perms:', unranker1)
Task: First power of 2 that has leading decimal digits of 12







Python: from math import log, modf, floor

def p(l, n, pwr=2):
    l = int(abs(l))
    digitcount = floor(log(l, 10))
    log10pwr = log(pwr, 10)
    raised, found = -1, 0
    while found < n:
        raised += 1
        firstdigits = floor(10**(modf(log10pwr * raised)[0] + digitcount))
        if firstdigits == l:
            found += 1
    return raised


if __name__ == '__main__':
    for l, n in [(12, 1), (12, 2), (123, 45), (123, 12345), (123, 678910)]:
        print(f"p({l}, {n}) =", p(l, n))
Task: Stirling numbers of the second kind







Python: computed = {}

def sterling2(n, k):
	key = str(n) + "," + str(k)

	if key in computed.keys():
		return computed[key]
	if n == k == 0:
		return 1
	if (n > 0 and k == 0) or (n == 0 and k > 0):
		return 0
	if n == k:
		return 1
	if k > n:
		return 0
	result = k * sterling2(n - 1, k) + sterling2(n - 1, k - 1)
	computed[key] = result
	return result

print("Stirling numbers of the second kind:")
MAX = 12
print("n/k".ljust(10), end="")
for n in range(MAX + 1):
	print(str(n).rjust(10), end="")
print()
for n in range(MAX + 1):
	print(str(n).ljust(10), end="")
	for k in range(n + 1):
		print(str(sterling2(n, k)).rjust(10), end="")
	print()
print("The maximum value of S2(100, k) = ")
previous = 0
for k in range(1, 100 + 1):
	current = sterling2(100, k)
	if current > previous:
		previous = current
	else:
		print("{0}\n({1} digits, k = {2})\n".format(previous, len(str(previous)), k - 1))
		break
Task: Cipolla's algorithm







Python: 

def convertToBase(n, b):
	if(n < 2):
		return [n];
	temp = n;
	ans = [];
	while(temp != 0):
		ans = [temp % b]+ ans;
		temp /= b;
	return ans;




def cipolla(n,p):
	n %= p
	if(n == 0 or n == 1):
		return (n,-n%p)
	phi = p - 1
	if(pow(n, phi/2, p) != 1):
		return ()
	if(p%4 == 3):
		ans = pow(n,(p+1)/4,p)
		return (ans,-ans%p)
	aa = 0
	for i in xrange(1,p):
		temp = pow((i*i-n)%p,phi/2,p)
		if(temp == phi):
			aa = i
			break;
	exponent = convertToBase((p+1)/2,2)
	def cipollaMult((a,b),(c,d),w,p):
		return ((a*c+b*d*w)%p,(a*d+b*c)%p)
	x1 = (aa,1)
	x2 = cipollaMult(x1,x1,aa*aa-n,p)
	for i in xrange(1,len(exponent)):
		if(exponent[i] == 0):
			x2 = cipollaMult(x2,x1,aa*aa-n,p)
			x1 = cipollaMult(x1,x1,aa*aa-n,p)
		else:
			x1 = cipollaMult(x1,x2,aa*aa-n,p)
			x2 = cipollaMult(x2,x2,aa*aa-n,p)
	return (x1[0],-x1[0]%p)

print "Roots of 2 mod 7: " +str(cipolla(2,7))
print "Roots of 8218 mod 10007: " +str(cipolla(8218,10007))
print "Roots of 56 mod 101: " +str(cipolla(56,101))
print "Roots of 1 mod 11: " +str(cipolla(1,11))
print "Roots of 8219 mod 10007: " +str(cipolla(8219,10007))
Task: Pierpont primes







Python: import random


def is_Prime(n):
    
    if n!=int(n):
        return False
    n=int(n)
    
    if n==0 or n==1 or n==4 or n==6 or n==8 or n==9:
        return False

    if n==2 or n==3 or n==5 or n==7:
        return True
    s = 0
    d = n-1
    while d%2==0:
        d>>=1
        s+=1
    assert(2**s * d == n-1)

    def trial_composite(a):
        if pow(a, d, n) == 1:
            return False
        for i in range(s):
            if pow(a, 2**i * d, n) == n-1:
                return False
        return True  

    for i in range(8):
        a = random.randrange(2, n)
        if trial_composite(a):
            return False

    return True

def pierpont(ulim, vlim, first):
    p = 0
    p2 = 1
    p3 = 1
    pp = []
    for v in xrange(vlim):
        for u in xrange(ulim):
            p = p2 * p3
            if first:
                p = p + 1
            else:
                p = p - 1
            if is_Prime(p):
                pp.append(p)
            p2 = p2 * 2
        p3 = p3 * 3
        p2 = 1
    pp.sort()
    return pp

def main():
    print "First 50 Pierpont primes of the first kind:"
    pp = pierpont(120, 80, True)
    for i in xrange(50):
        print "%8d " % pp[i],
        if (i - 9) % 10 == 0:
            print
    print "First 50 Pierpont primes of the second kind:"
    pp2 = pierpont(120, 80, False)
    for i in xrange(50):
        print "%8d " % pp2[i],
        if (i - 9) % 10 == 0:
            print
    print "250th Pierpont prime of the first kind:", pp[249]
    print "250th Pierpont prime of the second kind:", pp2[249]

main()
Task: N-smooth numbers







Python: primes = [2, 3, 5, 7, 11, 13, 17, 19, 23]

def isPrime(n):
    if n < 2:
        return False

    for i in primes:
        if n == i:
            return True
        if n % i == 0:
            return False
        if i * i > n:
            return True
    print "Oops,", n, " is too large"

def init():
    s = 24
    while s < 600:
        if isPrime(s - 1) and s - 1 > primes[-1]:
            primes.append(s - 1)
        if isPrime(s + 1) and s + 1 > primes[-1]:
            primes.append(s + 1)
        s += 6

def nsmooth(n, size):
    if n < 2 or n > 521:
        raise Exception("n")
    if size < 1:
        raise Exception("n")

    bn = n
    ok = False
    for prime in primes:
        if bn == prime:
            ok = True
            break
    if not ok:
        raise Exception("must be a prime number: n")

    ns = [0] * size
    ns[0] = 1

    next = []
    for prime in primes:
        if prime > bn:
            break
        next.append(prime)

    indicies = [0] * len(next)
    for m in xrange(1, size):
        ns[m] = min(next)
        for i in xrange(0, len(indicies)):
            if ns[m] == next[i]:
                indicies[i] += 1
                next[i] = primes[i] * ns[indicies[i]]

    return ns

def main():
    init()

    for p in primes:
        if p >= 30:
            break
        print "The first", p, "-smooth numbers are:"
        print nsmooth(p, 25)
        print

    for p in primes[1:]:
        if p >= 30:
            break
        print "The 3000 to 3202", p, "-smooth numbers are:"
        print nsmooth(p, 3002)[2999:]
        print

    for p in [503, 509, 521]:
        print "The 30000 to 3019", p, "-smooth numbers are:"
        print nsmooth(p, 30019)[29999:]
        print

main()
Task: Partition an integer x into n primes







Python: from itertools import combinations as cmb


def isP(n):
    if n == 2:
        return True
    if n % 2 == 0:
        return False
    return all(n % x > 0 for x in range(3, int(n ** 0.5) + 1, 2))


def genP(n):
    p = [2]
    p.extend([x for x in range(3, n + 1, 2) if isP(x)])
    return p


data = [
    (99809, 1), (18, 2), (19, 3), (20, 4), (2017, 24),
    (22699, 1), (22699, 2), (22699, 3), (22699, 4), (40355, 3)]


for n, cnt in data:
    ci = iter(cmb(genP(n), cnt))
    while True:
        try:
            c = next(ci)
            if sum(c) == n:
                print(' '.join(
                    [repr((n, cnt)), "->", '+'.join(str(s) for s in c)]
                ))
                break
        except StopIteration:
            print(repr((n, cnt)) + " -> Not possible")
            break
Task: Stirling numbers of the first kind







Python: computed = {}

def sterling1(n, k):
	key = str(n) + "," + str(k)

	if key in computed.keys():
		return computed[key]
	if n == k == 0:
		return 1
	if n > 0 and k == 0:
		return 0
	if k > n:
		return 0
	result = sterling1(n - 1, k - 1) + (n - 1) * sterling1(n - 1, k)
	computed[key] = result
	return result

print("Unsigned Stirling numbers of the first kind:")
MAX = 12
print("n/k".ljust(10), end="")
for n in range(MAX + 1):
	print(str(n).rjust(10), end="")
print()
for n in range(MAX + 1):
	print(str(n).ljust(10), end="")
	for k in range(n + 1):
		print(str(sterling1(n, k)).rjust(10), end="")
	print()
print("The maximum value of S1(100, k) = ")
previous = 0
for k in range(1, 100 + 1):
	current = sterling1(100, k)
	if current > previous:
		previous = current
	else:
		print("{0}\n({1} digits, k = {2})\n".format(previous, len(str(previous)), k - 1))
		break
Task: Ramer-Douglas-Peucker line simplification







Python: from __future__ import print_function
from shapely.geometry import LineString
 
if __name__=="__main__":
	line = LineString([(0,0),(1,0.1),(2,-0.1),(3,5),(4,6),(5,7),(6,8.1),(7,9),(8,9),(9,9)])
	print (line.simplify(1.0, preserve_topology=False))
Task: Bilinear interpolation







Python: 
import numpy as np
from scipy.misc import imread, imshow
from scipy import ndimage

def GetBilinearPixel(imArr, posX, posY):
	out = []

	
	modXi = int(posX)
	modYi = int(posY)
	modXf = posX - modXi
	modYf = posY - modYi
	modXiPlusOneLim = min(modXi+1,imArr.shape[1]-1)
	modYiPlusOneLim = min(modYi+1,imArr.shape[0]-1)

	
	for chan in range(imArr.shape[2]):
		bl = imArr[modYi, modXi, chan]
		br = imArr[modYi, modXiPlusOneLim, chan]
		tl = imArr[modYiPlusOneLim, modXi, chan]
		tr = imArr[modYiPlusOneLim, modXiPlusOneLim, chan]
	
		
		b = modXf * br + (1. - modXf) * bl
		t = modXf * tr + (1. - modXf) * tl
		pxf = modYf * t + (1. - modYf) * b
		out.append(int(pxf+0.5))

	return out

if __name__=="__main__":
	
	im = imread("test.jpg", mode="RGB")
	enlargedShape = list(map(int, [im.shape[0]*1.6, im.shape[1]*1.6, im.shape[2]]))
	enlargedImg = np.empty(enlargedShape, dtype=np.uint8)
	rowScale = float(im.shape[0]) / float(enlargedImg.shape[0])
	colScale = float(im.shape[1]) / float(enlargedImg.shape[1])

	for r in range(enlargedImg.shape[0]):
		for c in range(enlargedImg.shape[1]):
			orir = r * rowScale 
			oric = c * colScale
			enlargedImg[r, c] = GetBilinearPixel(im, oric, orir)

	imshow(enlargedImg)
Task: Vector







Python: v1 = PVector(5, 7)
v2 = PVector(2, 3)

println('{} {} {} {}\n'.format( v1.x, v1.y, v1.mag(), v1.heading()))


println(v1 + v2) 
println(v1 - v2) 
println(v1 * 11) 
println(v1 / 2)  
println('')


println(v1.sub(v1))  
println(v1.add(v2))  
println(v1.mult(10)) 
println(v1.div(10))