From 489e524385b70813ab80a9efa84f2a00f3ddbcee Mon Sep 17 00:00:00 2001
From: Dmitry Kokorin <dmitry@kokorin.org>
Date: Thu, 17 Mar 2016 19:12:35 +0300
Subject: [PATCH] triangle: iteration 2

---
 cpp/triangle/triangle.cpp | 35 ++++++++++-------------------------
 1 file changed, 10 insertions(+), 25 deletions(-)

diff --git a/cpp/triangle/triangle.cpp b/cpp/triangle/triangle.cpp
index c7ee869..43c3d83 100644
--- a/cpp/triangle/triangle.cpp
+++ b/cpp/triangle/triangle.cpp
@@ -10,7 +10,6 @@ using namespace std;
 
 namespace {
 
-
 inline bool fuzzy_equal(double a, double b)
 {
     typedef numeric_limits<double> limits_t;
@@ -24,39 +23,25 @@ inline bool fuzzy_equal(double a, double b)
         || abs(a - b) < min;
 }
 
-inline bool is_valid(double a, double b, double c)
-{
-    return a > 0 && b > 0 && c > 0
-        && a + b > c
-        && a + c > b
-        && b + c > a;
 }
 
-inline bool is_equilateral(double a, double b, double c)
-{
-    return fuzzy_equal(a, b)
-        && fuzzy_equal(a, c)
-        && fuzzy_equal(b, c);
-}
-
-inline bool is_isosceles(double a, double b, double c)
-{
-    return fuzzy_equal(a, b)
-        || fuzzy_equal(a, c)
-        || fuzzy_equal(b, c);
-}
-
-}
 
 kind_t kind(double a, double b, double c)
 {
-    if (!is_valid(a, b, c))
+    if (a > b) swap(a, b);
+    if (a > c) swap(a, c);
+    if (b > c) swap(b, c);
+
+    if (a <= 0)
         throw domain_error("invalid triangle");
 
-    if (is_equilateral(a, b, c))
+    if (a + b <= c)
+        throw domain_error("");
+
+    if (fuzzy_equal(a, c))
         return equilateral;
 
-    if (is_isosceles(a, b, c))
+    if (fuzzy_equal(a, b) || fuzzy_equal(b, c))
         return isosceles;
 
     return scalene;