collatz

1 files changed, 28 insertions, 0 deletions

diff --git a/examples/collatz.cff b/examples/collatz.cff
new file mode 100644
index 0000000..65b504a
--- /dev/null
+++ b/examples/collatz.cff
@@ -0,0 +1,28 @@
+import "libc.hff";
+
+extern fn main() void {
+   let mem *int = malloc(sizeof int * 4000);
+
+   let cmax = 0;
+   for let nv = 1; nv < 1000; ++nv {
+      let n = nv, 
+      c = 0;
+      while n != 1 {
+         if n < nv {
+            c += mem[n];
+            break;
+         }
+         if (n & 1) != 0 {
+            n = (3 * n) + 1;
+         } else {
+            n /= 2;
+         }
+         ++c;
+      }
+      mem[nv] = c;
+      if c > cmax {
+         cmax = c;
+      }
+   }
+   printf("should print 178: %d\n", cmax);
+}