Add tasks for all the new languages

Task/Semiprime/ERRE/semiprime.erre

@@ -0,0 +1,26 @@
+PROGRAM SEMIPRIME_NUMBER
+
+!VAR I%
+
+PROCEDURE SEMIPRIME(N%->RESULT%)
+   LOCAL F%,P%
+   P%=2
+   LOOP
+       EXIT IF NOT(F%<2 AND P%*P%<=N%)
+       WHILE (N% MOD P%)=0 DO
+            N%=N% DIV P%
+            F%+=1
+       END WHILE
+       P%+=1
+    END LOOP
+    RESULT%=F%-(N%>1)=2
+END PROCEDURE
+
+BEGIN
+    PRINT(CHR$(12);) !CLS
+    FOR I%=2 TO 100 DO
+         SEMIPRIME(I%->RESULT%)
+         IF RESULT% THEN PRINT(I%;) END IF
+    END FOR
+    PRINT
+END PROGRAM

Task/Semiprime/EchoLisp/semiprime.echolisp

@@ -0,0 +1,20 @@
+(lib 'math)
+(define (semi-prime? n)
+   (= (length (prime-factors n)) 2))
+
+(for ((i 100))
+    (when (semi-prime? i) (write i)))
+
+4 6 9 10 14 15 21 22 25 26 33 34 35 38 39 46 49 51 55 57 58 62 65 69 74 77 82 85 86 87 91 93 94 95
+
+(lib 'bigint)
+(define N (* (random-prime 10000000) (random-prime 10000000)))
+   → 6764578882969
+(semi-prime? N)
+    → #t
+
+;; a pair n,n+1 of semi-primes
+(prime-factors 100000000041)
+    → (3 33333333347)
+(prime-factors 100000000042)
+    → (2 50000000021)

Task/Semiprime/Oforth/semiprime.oforth

@@ -0,0 +1,4 @@
+func: semiprime(n)
+| i |
+   0 2 n sqrt asInteger for: i [ while(n i /mod swap 0 &=) [ ->n 1+ ] drop ]
+   n 1 > ifTrue: [ 1+ ] 2 == ;

Task/Semiprime/Ring/semiprime.ring

@@ -0,0 +1,24 @@
+prime = 1679
+decomp(prime)
+
+func decomp nr
+x = ""
+sum = 0
+for i = 1 to nr
+    if isPrime(i) and nr % i = 0
+       sum = sum + 1
+       x = x + string(i) + " * " ok
+    if i = nr and sum = 2
+       x2 = substr(x,1,(len(x)-2))
+       see string(nr) + " = " + x2 + "is semiprime" + nl
+    but i = nr and sum != 2 see string(nr) + " is not semiprime" + nl ok
+next
+
+func isPrime n
+     if n < 2 return false ok
+     if n < 4 return true ok
+     if n % 2 = 0 return false ok
+     for d = 3 to sqrt(n) step 2
+         if n % d = 0 return false ok
+     next	
+     return true

Task/Semiprime/Sidef/semiprime.sidef

@@ -0,0 +1,12 @@
+require('ntheory');
+
+func is_semiprime(n) {
+    static nt = %S'ntheory';
+    if (var p = [nt.trial_factor(n, 500)]) {
+        return false if (p.len > 2);
+        return !!nt.is_prime(p[1]) if (p.len == 2);
+  }
+  [nt.factor(n)].len == 2;
+}
+
+say [2,4,99,100,1679,32768,1234567,9876543,900660121].grep{ is_semiprime(_) }

Task/Semiprime/Swift/semiprime.swift

@@ -0,0 +1,37 @@
+import Foundation
+
+func primes(n: Int) -> AnyGenerator<Int> {
+
+  var (seive, i) = ([Int](0..<n), 1)
+  let lim = Int(sqrt(Double(n)))
+
+  return anyGenerator {
+    while ++i < n {
+      if seive[i] != 0 {
+        if i <= lim {
+          for notPrime in stride(from: i*i, to: n, by: i) {
+            seive[notPrime] = 0
+          }
+        }
+        return i
+      }
+    }
+    return nil
+  }
+}
+
+func isSemiPrime(n: Int) -> Bool {
+  let g = primes(n)
+  while let first = g.next() {
+    if n % first == 0 {
+      if first * first == n {
+        return true
+      } else {
+        while let second = g.next() {
+          if first * second == n { return true }
+        }
+      }
+    }
+  }
+  return false
+}