langs a-z

Task/Factorial/Piet/factorial.piet

@@ -0,0 +1,37 @@
+push 1
+not
+in(number)
+duplicate
+not        // label a
+pointer    // pointer 1
+duplicate
+push 1
+subtract
+push 1
+pointer
+push 1
+noop
+pointer
+duplicate  // the next op is back at label a
+
+push 1     // this part continues from pointer 1
+noop
+push 2     // label b
+push 1
+rot 1 2
+duplicate
+not
+pointer    // pointer 2
+multiply
+push 3
+pointer
+push 3
+pointer
+push 3
+push 3
+pointer
+pointer    // back at label b
+
+pop        // continues from pointer 2
+out(number)
+exit