Data commit

Task/Prime-decomposition/D/prime-decomposition.d

@@ -0,0 +1,27 @@
+import std.stdio, std.bigint, std.algorithm, std.traits, std.range;
+
+Unqual!T[] decompose(T)(in T number) pure nothrow
+in {
+    assert(number > 1);
+} body {
+    typeof(return) result;
+    Unqual!T n = number;
+
+    for (Unqual!T i = 2; n % i == 0; n /= i)
+        result ~= i;
+    for (Unqual!T i = 3; n >= i * i; i += 2)
+        for (; n % i == 0; n /= i)
+            result ~= i;
+
+    if (n != 1)
+        result ~= n;
+    return result;
+}
+
+void main() {
+    writefln("%(%s\n%)", iota(2, 10).map!decompose);
+    decompose(1023 * 1024).writeln;
+    BigInt(2 * 3 * 5 * 7 * 11 * 11 * 13 * 17).decompose.writeln;
+    decompose(16860167264933UL.BigInt * 179951).writeln;
+    decompose(2.BigInt ^^ 100_000).group.writeln;
+}