Partition an integer x into n primes: Difference between revisions

Content added Content deleted

Inline

@@ Line 1,075: / Line 1,075: @@
 =={{header|Mathematica}}==
+This can be done with IntegerPartitions:
-{{output?|Mathematica}}
+<lang Mathematica>partition[x_,n_]:= "Partitioned "<>ToString[x]<>" with "<>ToString[n]<>" primes: "<>StringRiffle[
+   ToString/@First[Sort[Sort/@Select[IntegerPartitions[x,{n},Prime/@Range[PrimePi[x]]],Length[Union[#]]===n&]],{"impossible"}]
+,"+"]
+partition[18, 2]
-{{incorrect|Mathematica| <br><br> the partitioning of &nbsp; '''40,356''' &nbsp; into three primes isn't the lowest primes that are possible, <br>
+partition[19, 3]
-the primes should be: <br><br> &nbsp; <big> '''3''', &nbsp; '''139''', &nbsp; '''40213'''. </big> &nbsp; <br>}}
+partition[20, 4]</lang>
-Just call the function F[X,N]
-<lang Mathematica>F[x_, n_] :=
- Print["Partitioned ", x, " with ", n, " primes: ",
-  StringRiffle[
-   ToString /@
-    Reverse[First@
-      Sort[Select[IntegerPartitions[x, {n}, Prime@Range@PrimePi@x],
-        Length@Union@# == n &], Last]], "+"]]
-F[40355, 3]</lang>
 {{out}}
 <pre>
-Partitioned 40355 with 3 primes: 5+7+40343
+Partitioned 18 with 2 primes: 5+13
+Partitioned 19 with 3 primes: 3+5+11
+Partitioned 20 with 4 primes: impossible
 </pre>