Data commit

Task/Arithmetic-Rational/Picat/arithmetic-rational.picat

@@ -0,0 +1,18 @@
+main =>
+    foreach (I in 2..2**19, is_perfect(I))
+        println(I)
+    end.
+
+is_perfect(N) => sum_rationals([$frac(1,D) : D in divisors(N)]) == $frac(2,1).
+
+divisors(N) = [I : I in 1..N, N mod I == 0].
+
+add(frac(A,B), frac(C,D)) = new_fract(A*D+B*C, B*D).
+
+new_fract(A,B) = $frac(Num, Den) =>
+    G = gcd(A,B),
+    Num = A // G,
+    Den = B // G.
+
+sum_rationals([X]) = X.
+sum_rationals([X,Y|T]) = sum_rationals([add(X,Y)|T]).