primes & composites

1 files changed, 52 insertions, 0 deletions

diff --git a/composites.tex b/composites.tex
new file mode 100644
index 0000000..eeac38f
--- /dev/null
+++ b/composites.tex
@@ -0,0 +1,52 @@
+\newcount\a
+\newcount\b
+\newcount\c
+\newcount\n
+\newcount\p
+\newcount\q
+
+\def\div#1:#2:#3:{%
+  \ifnum#1>#2 %
+    \advance#1 by-#2 %
+    \div#1:#2:#3:%
+  \else%
+    \ifnum#1=#2 %
+      #3=1%
+    \else%
+      #3=0%
+    \fi%
+  \fi%
+}
+
+\long\def\isprime#1:#2:#3:{%
+  #3=0%
+  \ifnum#1>#2 %
+    \a=#1 %
+    \div\a:#2:\c: %
+    \ifnum\c=0 %
+      \b=#2 %
+      \advance\b by 1 %
+      \isprime#1:\the\b:#3:%
+    \else
+      #1\par%
+    \fi%
+  \else%
+    #3=1%
+  \fi%
+}
+
+\def\listprimes#1:#2:#3:#4:{%
+  \isprime\the#1:2:#4: %
+  \ifnum#4=0 %
+    \advance#2 by 1 %
+  \fi
+  \ifnum#2<#3 %
+    \advance#1 by 1 %
+    \listprimes#1:#2:#3:#4: %
+  \fi
+}
+
+\listprimes\p:\n:11:\q:
+
+\end
+