June 2018 Update

Task/Pernicious-numbers/00DESCRIPTION

@@ -1,4 +1,6 @@
-A   [[wp:Pernicious number|pernicious number]]   is a positive integer whose   [[population count]]   is a prime.   The population count is the number of ones in the binary representation of a non-negative integer.
+A   [[wp:Pernicious number|pernicious number]]   is a positive integer whose   [[population count]]   is a prime.
+
+The population count is the number of   ''ones''   in the binary representation of a non-negative integer.
 
 
 ;Example
@@ -6,7 +8,7 @@ A   [[wp:Pernicious number|pernicious number]]   is a positive integer
 
 
 ;Task
-* display the first   '''25'''   pernicious numbers.
+* display the first   '''25'''   pernicious numbers   (in decimal).
 * display all pernicious numbers between   '''888,888,877'''   and   '''888,888,888'''   (inclusive).
 * display each list of integers on one line   (which may or may not include a title).
 

Task/Pernicious-numbers/AWK/pernicious-numbers.awk

@@ -0,0 +1,54 @@
+# syntax: GAWK -f PERNICIOUS_NUMBERS.AWK
+BEGIN {
+    pernicious(25)
+    pernicious(888888877,888888888)
+    exit(0)
+}
+function pernicious(x,y,  count,n) {
+    if (y == "") { # print first X pernicious numbers
+      while (count < x) {
+        if (is_prime(pop_count(++n)) == 1) {
+          printf("%d ",n)
+          count++
+        }
+      }
+    }
+    else { # print pernicious numbers in X-Y range
+      for (n=x; n<=y; n++) {
+        if (is_prime(pop_count(n)) == 1) {
+          printf("%d ",n)
+        }
+      }
+    }
+    print("")
+}
+function dec2bin(n,  str) {
+    while (n) {
+      if (n%2 == 0) {
+        str = "0" str
+      }
+      else {
+        str = "1" str
+      }
+      n = int(n/2)
+    }
+    if (str == "") {
+      str = "0"
+    }
+    return(str)
+}
+function is_prime(x,  i) {
+    if (x <= 1) {
+      return(0)
+    }
+    for (i=2; i<=int(sqrt(x)); i++) {
+      if (x % i == 0) {
+        return(0)
+      }
+    }
+    return(1)
+}
+function pop_count(n) {
+    n = dec2bin(n)
+    return gsub(/1/,"&",n)
+}

Task/Pernicious-numbers/Factor/pernicious-numbers.factor

@@ -0,0 +1,6 @@
+USING: lists lists.lazy math.bits math.primes math.ranges ;
+
+: pernicious? ( n -- ? ) make-bits [ t = ] count prime? ;
+
+0 lfrom [ pernicious? ] lfilter 25 swap ltake list>array . ! print first 25 pernicious numbers
+888,888,877 888,888,888 [a,b] [ pernicious? ] filter .     ! print pernicious numbers in range

Task/Pernicious-numbers/Haskell/pernicious-numbers-2.hs

@@ -0,0 +1,26 @@
+import Data.List (unfoldr)
+import Data.Tuple (swap)
+
+isPernicious :: Int -> Bool
+isPernicious = isPrime . popCount
+
+popCount :: Int -> Int
+popCount =
+  sum . unfoldr ((flip if_ Nothing . (0 ==)) <*> (Just . swap . flip quotRem 2))
+
+isPrime :: Int -> Bool
+isPrime =
+  (==) <$> (\n -> [1 .. n] >>= flip ((if_ . (0 ==) . mod n) <*> return) []) <*>
+  ((1 :) . return)
+
+if_ :: Bool -> a -> a -> a
+if_ True x _ = x
+if_ False _ y = y
+
+main :: IO ()
+main =
+  mapM_
+    print
+    [ take 25 $ filter isPernicious [1 ..]
+    , filter isPernicious [888888877 .. 888888888]
+    ]

Task/Pernicious-numbers/Julia/pernicious-numbers.julia

@@ -1,19 +1,16 @@
-ispernicious(n::Int) = isprime(count_ones(n))
+using Primes
 
-pcnt = 0
-i = 0
-print("    ")
-while pcnt < 25
-    i += 1
-    ispernicious(i) || continue
-    pcnt += 1
-    print(i, " ")
+ispernicious(n::Integer) = isprime(count_ones(n))
+nextpernicious(n::Integer) = begin n += 1; while !ispernicious(n) n += 1 end; return n end
+function perniciouses(n::Int)
+    rst = Vector{Int}(n)
+    rst[1] = 3
+    for i in 2:n
+        rst[i] = nextpernicious(rst[i-1])
+    end
+    return rst
 end
-println()
+perniciouses(a::Integer, b::Integer) = filter(ispernicious, a:b)
 
-print("    ")
-for i in 888888877:888888888
-    ispernicious(i) || continue
-    print(i, " ")
-end
-println()
+println("First 25 pernicious numbers: ", join(perniciouses(25), ", "))
+println("Perniciouses in [888888877, 888888888]: ", join(perniciouses(888888877, 888888888), ", "))

Task/Pernicious-numbers/Modula-2/pernicious-numbers.mod2

@@ -0,0 +1,50 @@
+MODULE Pernicious;
+FROM FormatString IMPORT FormatString;
+FROM Terminal IMPORT WriteString,WriteLn,ReadChar;
+
+PROCEDURE IsPrime(x : LONGINT) : BOOLEAN;
+VAR i : LONGINT;
+BEGIN
+    IF x<2 THEN RETURN FALSE END;
+    FOR i:=2 TO x-1 DO
+        IF x MOD i = 0 THEN RETURN FALSE END
+    END;
+    RETURN TRUE
+END IsPrime;
+
+PROCEDURE BitCount(x : LONGINT) : LONGINT;
+VAR count : LONGINT;
+BEGIN
+    count := 0;
+    WHILE x>0 DO
+        x := x BAND (x-1);
+        INC(count)
+    END;
+    RETURN count
+END BitCount;
+
+VAR
+    buf : ARRAY[0..63] OF CHAR;
+    i,n : LONGINT;
+BEGIN
+    i := 1;
+    n := 0;
+    WHILE n<25 DO
+        IF IsPrime(BitCount(i)) THEN
+            FormatString("%l ", buf, i);
+            WriteString(buf);
+            INC(n)
+        END;
+        INC(i)
+    END;
+    WriteLn;
+
+    FOR i:=888888877 TO 888888888 DO
+        IF IsPrime(BitCount(i)) THEN
+            FormatString("%l ", buf, i);
+            WriteString(buf)
+        END;
+    END;
+
+    ReadChar
+END Pernicious.

Task/Pernicious-numbers/Ring/pernicious-numbers.ring

@@ -0,0 +1,42 @@
+# Project : Pernicious numbers
+# Date    : 2017/10/01
+# Author : Gal Zsolt (~ CalmoSoft ~)
+# Email   : <calmosoft@gmail.com>
+
+see "The first 25 pernicious numbers:" + nl
+nr = 0
+for n=1 to 50
+    sum = 0
+    str = decimaltobase(n, 2)
+    for m=1 to len(str)
+        if str[m] = "1"
+           sum = sum + 1
+        ok
+    next
+    if isprime(sum)
+       nr = nr + 1
+       see "" + n + " "
+    ok
+    if nr = 25
+       exit
+    ok
+next
+
+func decimaltobase(nr, base)
+     binary = 0
+     i = 1
+     while(nr != 0)
+           remainder = nr % base
+           nr = floor(nr/base)
+           binary= binary + (remainder*i)
+           i = i*10
+     end
+     return string(binary)
+
+func isprime num
+     if (num <= 1) return 0 ok
+     if (num % 2 = 0 and num != 2) return 0 ok
+     for i = 3 to floor(num / 2) -1 step 2
+         if (num % i = 0) return 0 ok
+     next
+     return 1