Sha256: c3ac32015148cea603c59dcf7fe892e0b246305842e8a3aa0f9f1fbf93008b87
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Versions: 20
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Stored size: 1.91 KB
Contents
module triangle;
import std.exception;
enum TriangleType { equilateral, isosceles, scalene };
/**
* Return what kind of triagle that is.
*/
TriangleType kind (double a, double b, double c)
{
// check the triangle inequality
if ( a + b <= c || a + c <= b || c + b <= a)
{
throw new Exception("Segment lengths do not satisfy triangle inequality.");
}
if (a == b && b == c) return TriangleType.equilateral;
else if (a == b || a == c || b == c) return TriangleType.isosceles;
else return TriangleType.scalene;
}
unittest
{
// equilateral_triangles_have_equal_sides
{
assert(TriangleType.equilateral == kind(2, 2, 2));
}
// larger_equilateral_triangles_also_have_equal_sides
{
assert(TriangleType.equilateral == kind(10, 10, 10));
}
// isosceles_triangles_have_last_two_sides_equal
{
assert(TriangleType.isosceles == kind(3, 4, 4));
}
// isosceles_triangles_have_first_and_last_sides_equal
{
assert(TriangleType.isosceles == kind(4, 3, 4));
}
// isosceles_triangles_have_first_two_sides_equal
{
assert(TriangleType.isosceles == kind(4, 4, 3));
}
// isosceles_triangles_have_in_fact_exactly_two_sides_equal
{
assert(TriangleType.isosceles == kind(10, 10, 2));
}
// scalene_triangles_have_no_equal_sides
{
assert(TriangleType.scalene == kind(3, 4, 5));
}
// scalene_triangles_have_no_equal_sides_at_a_larger_scale_too
{
assert(TriangleType.scalene == kind(10, 11, 12));
}
// scalene_triangles_have_no_equal_sides_in_descending_order_either
{
assert(TriangleType.scalene == kind(5, 4, 2));
}
// very_small_triangles_are_legal
{
assert(TriangleType.scalene == kind(0.4, 0.6, 0.3));
}
// triangles_with_no_size_are_illegal
{
assertThrown(kind(0, 0, 0));
}
// triangles_with_negative_sides_are_illegal
{
assertThrown(kind(3, 4, -5));
}
// triangles_violating_triangle_inequality_are_illegal
{
assertThrown(kind(1, 1, 3));
}
// larger_triangles_violating_triangle_inequality_are_illegal
{
assertThrown(kind(7, 3, 2));
}
}
Version data entries
20 entries across 20 versions & 1 rubygems