September 2017 Update

Task/Executable-library/Phix/executable-library-1.phix

@@ -0,0 +1,64 @@
+function isMainOrInclude()
+-- returns 1 if called from the main file, 0 if from an include
+integer res
+    #ilASM{
+        [32]
+            mov eax,[ebp+20]    -- prev_ebp
+            mov eax,[eax+8]     -- rtn
+            mov [res],eax
+        [64]
+            mov rax,[rbp+40]    -- prev_ebp
+            mov rax,[rax+16]    -- rtn
+            mov [res],rax
+        []
+          }
+    return res=21 -- (21=T_maintls)
+end function
+
+--global (if you want to be able to call this from test.exw)
+function hailstone(atom n)
+sequence s = {n}
+    while n!=1 do
+        if remainder(n,2)=0 then
+            n /= 2
+        else
+            n = 3*n+1
+        end if
+        s &= n
+    end while
+    return s
+end function
+
+global function hailstone_count(atom n)
+integer count = 1
+    while n!=1 do
+        if remainder(n,2)=0 then
+            n /= 2
+        else
+            n = 3*n+1
+        end if
+        count += 1
+    end while
+    return count
+end function
+
+if isMainOrInclude() then
+
+    sequence s = hailstone(27)
+    integer ls = length(s)
+    s[5..-5] = {".."}
+    puts(1,"hailstone(27) = ")
+    ? s
+    printf(1,"length = %d\n\n",ls)
+
+    integer hmax = 1, imax = 1,count
+    for i=2 to 1e5-1 do
+        count = hailstone_count(i)
+        if count>hmax then
+            hmax = count
+            imax = i
+        end if
+    end for
+
+    printf(1,"The longest hailstone sequence under 100,000 is %d with %d elements.\n",{imax,hmax})
+end if

Task/Executable-library/Phix/executable-library-2.phix

@@ -0,0 +1,11 @@
+include hail.exw
+
+sequence counts = {}
+for i=1 to 100000 do
+    integer l = hailstone_count(i)
+    if length(counts)<l then
+        counts &= repeat(0,l-length(counts))
+    end if
+    counts[l] += 1
+end for
+printf(1,"The hailstone length returned most often between 1 and 100,000 is %d.\n",{largest(counts,1)})

Task/Executable-library/Zkl/executable-library-1.zkl

@@ -0,0 +1,12 @@
+fcn collatz(n,z=L()){ z.append(n); if(n==1) return(z);
+   if(n.isEven) return(self.fcn(n/2,z)); return(self.fcn(n*3+1,z)) }
+
+h27:=collatz(27);
+println("Hailstone(27)-->",h27[0,4].concat(","),"...",
+	h27[-4,*].concat(",")," length ",h27.len());
+
+[2..0d100_000].pump(Void,  // loop n from 2 to 100,000
+   collatz,              // generate Collatz sequence(n)
+   fcn(c,n){           // if new longest sequence, save length/C, return longest
+      if(c.len()>n[0]) n.clear(c.len(),c[0]); n}.fp1(L(0,0)))
+.println();

Task/Executable-library/Zkl/executable-library-2.zkl

@@ -0,0 +1,12 @@
+#!/home/craigd/Bin/zkl
+collatz:=Import("hailstone",False,False,False).collatz; // don't run constructor
+d:=Dictionary();
+[2..0d100_000].pump(Void,  // loop n from 2 to 100,000
+   collatz,       // generate Collatz sequence(n)
+   'wrap(c){ d.incV(c.len()) }      // save length
+);
+println("Number of different lengths: ",d.len());
+longest:=(0).max(d.values);
+mostFreqLen:=d.filter1('wrap([(k,v)]){ v==longest })[0];
+println("Most frequent length: %d; %d sequences of that length."
+        .fmt(mostFreqLen,longest));