Data commit

Task/Prime-decomposition/XPL0/prime-decomposition.xpl0

@@ -0,0 +1,40 @@
+\ Prime decomposition
+code Abs=0, Rem=2, CrLf=9, IntIn=10, IntOut=11, Text=12;
+define MaxFacIndex = 30;
+\ -(2^31) has most prime factors (31 twos) than other 32-bit signed integer.
+integer I, N, Facs(MaxFacIndex), FacsCnt;
+
+  procedure CalcFacs(N, Facs, FacsCnt);
+  integer N, Facs, FacsCnt;
+  integer I, Cnt;
+  begin
+  N:= Abs(N);
+  Cnt:=0;
+  if N >= 2 then
+    begin
+    I:= 2;
+    while I * I <= N do
+      begin
+      if Rem(N / I) = 0 then
+        begin
+        N:= N / I;
+        Facs(Cnt):= I; Cnt:= Cnt + 1;
+        I:= 2
+        end
+      else
+        I:= I + 1
+      end;
+    Facs(Cnt):= N; Cnt:= Cnt + 1
+    end;
+  FacsCnt(0):= Cnt
+  end;
+
+begin
+Text(0, "Enter a number: "); N:= IntIn(0);
+CalcFacs(N, Facs, addr FacsCnt);
+for I:= 0 to FacsCnt - 2 do
+  begin
+  IntOut(0, Facs(I)); Text(0, " ")
+  end;
+IntOut(0, Facs(FacsCnt - 1)); CrLf(0)
+end