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Task/Heronian-triangles/Sidef/heronian-triangles.sidef

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+class Triangle(a, b, c) {
+
+  has (sides, perimeter, area)
+
+  method init {
+    sides = [a, b, c].sort
+    perimeter = [a, b, c].sum
+    var s = (perimeter / 2)
+    area = sqrt(s * (s - a) * (s - b) * (s - c))
+  }
+
+  method is_valid(a,b,c) {
+    var (short, middle, long) = [a, b, c].sort...;
+    (short + middle) > long
+  }
+
+  method is_heronian {
+    area == area.to_i
+  }
+
+  method <=>(other) {
+    [area, perimeter, sides] <=> [other.area, other.perimeter, other.sides]
+  }
+
+  method to_s {
+    "%-11s%6d%8.1f" % (sides.join('x'), perimeter, area)
+  }
+}
+
+var (max, area) = (200, 210)
+var prim_triangles = []
+
+for a in (1..max) {
+  for b in (a..max) {
+    for c in (b..max) {
+      next if (Math.gcd(a, b, c) > 1)
+      prim_triangles << Triangle(a, b, c) if Triangle.is_valid(a, b, c)
+    }
+  }
+}
+
+var sorted = prim_triangles.grep{.is_heronian}.sort
+
+say "Primitive heronian triangles with sides upto #{max}: #{sorted.size}"
+say "\nsides       perim.   area"
+say sorted.first(10).join("\n")
+say "\nTriangles with an area of: #{area}"
+sorted.each{|tr| say tr if (tr.area == area)}