June 2018 Update

Task/Polynomial-long-division/REXX/polynomial-long-division.rexx

@@ -0,0 +1,44 @@
+/* REXX needed by some... */
+z='1 -12 0 -42'  /* Numerator   */
+n='1 -3'         /* Denominator */
+zx=z
+nx=n copies('0 ',words(z)-words(n))
+qx=''            /* Quotient    */
+Do Until words(zx)<words(n)
+  Parse Value div(zx,nx) With q zx
+  qx=qx q
+  nx=subword(nx,1,words(nx)-1)
+  End
+Say '('show(z)')/('show(n)')=('show(qx)')'
+Say 'Remainder:' show(zx)
+Exit
+div: Procedure
+Parse Arg z,n
+q=word(z,1)/word(n,1)
+zz=''
+Do i=1 To words(z)
+  zz=zz word(z,i)-q*word(n,i)
+  End
+Return q subword(zz,2)
+
+show: Procedure
+Parse Arg poly
+d=words(poly)-1
+res=''
+Do i=1 To words(poly)
+  Select
+    When d>1 Then fact='*x**'d
+    When d=1 Then fact='*x'
+    Otherwise     fact=''
+    End
+  Select
+    When word(poly,i)=0  Then p=''
+    When word(poly,i)=1  Then p='+'substr(fact,2)
+    When word(poly,i)=-1 Then p='-'substr(fact,2)
+    When word(poly,i)<0  Then p=word(poly,i)||fact
+    Otherwise                 p='+'word(poly,i)||fact
+    End
+  res=res p
+  d=d-1
+  End
+Return strip(space(res,0),'L','+')