Data commit

Task/Hailstone-sequence/MATLAB/hailstone-sequence-1.m

@@ -0,0 +1,11 @@
+function x = hailstone(n)
+  x = n;
+  while n > 1
+       % faster than mod(n, 2)
+    if n ~= floor(n / 2) * 2
+      n = n * 3 + 1;
+    else
+      n = n / 2;
+    end
+    x(end + 1) = n; %#ok
+  end

Task/Hailstone-sequence/MATLAB/hailstone-sequence-2.m

@@ -0,0 +1,2 @@
+x = hailstone(27);
+fprintf('hailstone(27): %d %d %d %d ... %d %d %d %d\nnumber of elements: %d\n', x(1:4), x(end-3:end), numel(x))

Task/Hailstone-sequence/MATLAB/hailstone-sequence-3.m

@@ -0,0 +1,9 @@
+N = 1e5;
+maxLen = 0;
+for k = 1:N
+  kLen = numel(hailstone(k));
+  if kLen > maxLen
+    maxLen = kLen;
+    n = k;
+  end
+end

Task/Hailstone-sequence/MATLAB/hailstone-sequence-4.m

@@ -0,0 +1,18 @@
+function [n, maxLen] = longestHailstone(N)
+  maxLen = 0;
+  for k = 1:N
+    a = k;
+    kLen = 1;
+    while a > 1
+      if a ~= floor(a / 2) * 2
+        a = a * 3 + 1;
+      else
+        a = a / 2;
+      end
+      kLen = kLen + 1;
+    end
+    if kLen > maxLen
+      maxLen = kLen;
+      n = k;
+    end
+  end

Task/Hailstone-sequence/MATLAB/hailstone-sequence-5.m

@@ -0,0 +1,3 @@
+>> [n, maxLen] = longestHailstone(1e5)
+n = 77031
+maxLen = 351

Task/Hailstone-sequence/MATLAB/hailstone-sequence-6.m

@@ -0,0 +1,22 @@
+function [n, maxLen] = longestHailstone(N)
+  lenList(N) = 0;
+  lenList(1) = 1;
+  maxLen = 0;
+  for k = 2:N
+    a = k;
+    kLen = 0;
+    while a >= k
+      if a == floor(a / 2) * 2
+        a = a / 2;
+      else
+        a = a * 3 + 1;
+      end
+      kLen = kLen + 1;
+    end
+    kLen = kLen + lenList(a);
+    lenList(k) = kLen;
+    if kLen > maxLen
+      maxLen = kLen;
+      n = k;
+    end
+  end

Task/Hailstone-sequence/MATLAB/hailstone-sequence-7.m

@@ -0,0 +1,3 @@
+>> [n, maxLen] = longestHailstone(1e5)
+n = 77031
+maxLen = 351