Prolog. задача о путешествии

есть перечень населенных пунктов, которые связаны определенным видом транспорта. требуется получить подробный путь из пункта А в пункт Б , если такое путешествие возможно

pass(auckland, hamilton, bus).
pass(bangkok, auckland, plane).
pass(frankfurt, bangkok, plane).
pass(frankfurt, singapore, plane).
pass(hamilton, raglan, bus).
pass(losAngeles, auckland, plane).
pass(metz, frankfurt, train).
pass(metz, paris, train).
pass(paris, losAngeles, plane).
pass(saarbruecken, frankfurt, train).
pass(saarbruecken, paris, train).
pass(valmont, metz, bus).
pass(valmont, saarbruecken, bus).

travel(X,Y) :-
  pass(X, Y, T) -> 
    write([T, X, Y]), ! , nl ;
  pass(X, Z, T1) ,
  pass(Z, Y, T2) -> 
    write([T1, X, Z, T2, Z, Y]), !, nl ;
  pass(X, Z1, T1) ,
  pass(Z1, Z2, T2) ,
  pass(Z2, Y, T3) -> 
    write([T1, X, Z1, T2, Z1, Z2, T3, Z2, Y]), !, nl ;
  pass(X, Z1,  T1) ,
  pass(Z1, Z2,  T2) ,
  pass(Z2, Z3, T3) ,
  pass(Z3, Y,  T4) -> 
    write([T1, X, Z1, T2, Z1, Z2, T3, Z2, Z3, T4, Z3, Y]), !, nl .

задачка о тортике, Си и Хаскель

ВиниПух и Пятачок сьели торт за t секунд. если бы ели тот же торт два Винни–Пуха, то у них торт был бы съеден на 1 минуту раньше, а если бы тот же самый торт ели два Пятачка, то они на 4 минуты больше бы времени затратили. так за сколько же времени съели торт друзья?

сначала Винни сжирает по-быстрому свою половину, а потом еще 1 минуту они хомячат вместе то, что Пятачок в одиночку ел бы дополнительные 5 мин - т.е. _вдвоем_ Винни и Пятачок едят как _пять_ Пятачков, т.е. Винни один ест за четверых Пятачков

-- import Debug.Trace
import Control.Monad
-- import System.IO
import System.Environment

pudding :: Double -> Double -> Double
pudding t1 t2 = 
  head $ [1..] >>= \t -> -- traceShow t $ 
    let p = (recip t) / 5 
        b = p * 4 
        f = \t0 v1 v2 -> guard $ 1e-8 >= (abs $ t0 * (v1 + v2) - 1) 
    in (f t b p) >> (f (t + t1) b b) >> (f (t + t2) p p) >> return t

main :: IO () 
main = 
  getEnv "vin" >>= \x -> getEnv "pig" >>= \y -> 
  return (pudding (read x) (read y)) >>= print
{-
  (pudding <$ putStr "медведи  : " <* hFlush stdout <*> readLn 
           <* putStr "поросята : " <* hFlush stdout <*> readLn) >>= print 

  getArgs >>= \args -> 
  if (length args == 2)  
  then return (pudding (read $ head args) (read $ head $ tail args)) >>= print 
  else putStrLn "usage: a.out  two_winnies_delta two_piggies_delta"
-}

и на сях:

#include <stdlib.h>
#include <stdio.h>

int comp (float, float, float) ;

int main (int argc, char** argv, char** envp)
{
  float t0 , t1 , t2 , p , b ; t0 = 60.0 ; 

  /* if (argc != 3) 
       { printf ("usage: two_winnies_delta two_piggies_delta\n") ; return 1 ; }
   t0 = 0.0 ; t1 = atof (argv[1]) ; t2 = atof (argv[2]) ;  */

  printf ("winnies : ") ; scanf ("%f", &t1) ;
  printf ("piggies : ") ; scanf ("%f", &t2) ;

  while (1) 
  {
    t0 = t0 + 1 ; p = 1 / (5 * t0) ; b = 4 * p ;   
    // printf ("%5.2f\n", t0) ;
    if ((comp (t0, p, b) == 1) & 
        (comp (t0 + t1, b, b) == 1) & 
        (comp (t0 + t2, p, p) == 1)) break ;
   }

  printf ("%5.2f\n", t0) ;
  return 0 ;
}

int comp (float t0, float t1, float t2)
{
  if ((t0 * (t1 + t2) - 1.0) < 0.00000001) return 1 ; else return 0 ;
}

Идрис 02

Double

    sqrt : Double -> Double
    exp  : Double -> Double
    log  : Double -> Double

    ceiling : Double -> Double
    floor   : Double -> Double

    euler : Double
    pi    : Double

    cos : Double -> Double
    sin : Double -> Double
    tan : Double -> Double

    acos : Double -> Double
    asin : Double -> Double
    atan : Double -> Double

    cosh : Double -> Double
    sinh : Double -> Double
    tanh : Double -> Double

one step

James Watt (University of Glasgow) realised that contemporary engine designs wasted a great deal of energy by repeatedly cooling and reheating the working cylinder. Watt's critical insight, arrived at in May 1765, was to cause the steam to condense in a separate chamber apart from the piston, and to maintain the temperature of the cylinder at the same temperature as the injected steam by surrounding it with a "steam jacket".

the difficulty of the manufacture of a large cylinder with a tightly fitting piston was solved by John Wilkinson. Watt also adapted his engine to produce rotary motion, greatly broadening its use beyond pumping water. in 1776, the first engines were installed and working in commercial enterprises

Идрис 01

comments

-- single-line

{-
      multi-line
-}

keywords

      case .. of
      constructor
      data
      export
      if .. then .. else ..
      implementation
      import
      interface
      let .. in
      module
      mutual
      namespace
      parameters
      private
      public export
      record
      total
      using
      where

primitive types:

      Int
      Integer
      Double
      Char
      String
      Bool : True | False
      Ptr 
      Bits8
      Bits16
      Bits32
      Bits64

ops

two steps

May 7, 1895, St-Petersburg. On this day, Popov performed a public demonstration of transmission and reception of radio waves used for communication at the Russian Physical and Chemical Society, using his coherer. Popov's early experiments were transmissions of only 550 m. Popov was the first to develop a practical communication system

The "Flyer" lifted from level ground to the north of Big Kill Devil Hill, North Carolina, at 10:35 a.m., on December 17, 1903. Orville Wright piloted the plane which weighed six hundred and five pounds. The first heavier-than-air, controlled, powered and sustained flight traveled one hundred twenty feet in twelve seconds

three steps

the first successful flight of V-2(A-4) was on 3 October 1942 (Peenemünde, Blizna). this rocket was 14 metres in length, 12500 kg of weight and can carry nearly a tonne of explosive. its propellant: 3810 kg (75% ethanol, 25% water) + 4910 kg of liquid oxygen. the combustion burner reached a temperature of 2500–2700°C. the rocket burned for 58 seconds and reached a height of 190 kilometres

16 July 1945 at 05:29:45 local time (Trinity Site, Socorro, New Mexico) the device Gadget exploded with an energy equivalent to around 20 kilotons of TNT. it left a crater of radioactive glass in the desert 3 m deep and 330 m wide. the shock wave was felt over 160 km away, and the mushroom cloud reached 12 km in height

Electronic Numerical Integrator And Calculator was completed in 1946 (University of Pennsylvania). it occupied about 200 m², used 17468 vacuum tubes, 15000 relays, weighing almost 50 tons and consuming 200 Kilowatts of electricity. it boasted speeds one thousand times faster than electro-mechanical machines