Data commit

Task/Heronian-triangles/VBA/heronian-triangles.vba

@@ -0,0 +1,52 @@
+Function heroArea(a As Integer, b As Integer, c As Integer) As Double
+    s = (a + b + c) / 2
+    On Error GoTo Err
+    heroArea = Sqr(s * (s - a) * (s - b) * (s - c))
+    Exit Function
+Err:
+    heroArea = -1
+End Function
+
+Function hero(h As Double) As Boolean
+    hero = (h - Int(h) = 0) And h > 0
+End Function
+
+Public Sub main()
+    Dim list() As Variant, items As Integer
+    Dim a As Integer, b As Integer, c As Integer
+    Dim hArea As Double
+    Dim tries As Long
+    For a = 1 To 200
+        For b = 1 To a
+            For c = 1 To b
+                tries = tries + 1
+                If gcd(gcd(a, b), c) = 1 Then
+                    hArea = heroArea(a, b, c)
+                    If hero(hArea) Then
+                        ReDim Preserve list(items)
+                        list(items) = Array(CStr(hArea), CStr(a + b + c), CStr(a), CStr(b), CStr(c))
+                        items = items + 1
+                    End If
+                End If
+            Next c
+        Next b
+    Next a
+    list = sort(list)
+    Debug.Print "Primitive Heronian triangles with sides up to 200:"; UBound(list) + 1; "(of"; tries; "tested)"
+    Debug.Print
+    Debug.Print "First 10 ordered by area/perimeter/sides:"
+    Debug.Print "area       perimeter        sides"
+    For i = 0 To 9
+        Debug.Print Format(list(i)(0), "@@@"), Format(list(i)(1), "@@@"),
+        Debug.Print list(i)(2); "x"; list(i)(3); "x"; list(i)(4)
+    Next i
+    Debug.Print
+    Debug.Print "area = 210:"
+    Debug.Print "area       perimeter        sides"
+    For i = 0 To UBound(list)
+        If Val(list(i)(0)) = 210 Then
+            Debug.Print Format(list(i)(0), "@@@"), Format(list(i)(1), "@@@"),
+            Debug.Print list(i)(2); "x"; list(i)(3); "x"; list(i)(4)
+        End If
+    Next i
+End Sub