tasks a-s

Task/Pascals-triangle/Metafont/pascals-triangle.metafont

@@ -0,0 +1,18 @@
+vardef bincoeff(expr n, k) =
+save ?;
+? := (1 for i=(max(k,n-k)+1) upto n: * i endfor )
+     / (1 for i=2 upto min(k, n-k): * i endfor); ?
+enddef;
+
+def pascaltr expr c =
+  string s_;
+  for i := 0 upto (c-1):
+    s_ := "" for k=0 upto (c-i): & "  " endfor;
+    s_ := s_ for k=0 upto i: & decimal(bincoeff(i,k))
+             & "  " if bincoeff(i,k)<9: & " " fi endfor;
+    message s_;
+  endfor
+enddef;
+
+pascaltr(4);
+end