From f77d5a95e78b64208b548cecd006f590a4341488 Mon Sep 17 00:00:00 2001
From: Dmitry Kokorin <dmitry@kokorin.org>
Date: Fri, 8 Apr 2016 14:12:40 +0300
Subject: [PATCH] say: passes tests

---
 cpp/say/say.cpp | 95 +++++++++++++++++++++++--------------------------
 cpp/say/say.h   |  2 +-
 2 files changed, 46 insertions(+), 51 deletions(-)

diff --git a/cpp/say/say.cpp b/cpp/say/say.cpp
index 44e2262..06e497f 100644
--- a/cpp/say/say.cpp
+++ b/cpp/say/say.cpp
@@ -1,8 +1,8 @@
 #include "say.h"
 
+#include <stdexcept>
 #include <unordered_map>
 
-#include <iostream>
 
 namespace say {
 
@@ -10,75 +10,70 @@ using namespace std;
 
 namespace {
 
-const unordered_map<number_t, string> numbers_map = {
-        {0, "zero"},
-        {1, "one"},
-        {2, "two"},
-        {3, "three"},
-        {4, "four"},
-        {5, "five"},
-        {6, "six"},
-        {7, "seven"},
-        {8, "eight"},
-        {9, "nine"},
+const unordered_map<number_t, string> number_map = {
+        {0,  "zero"},
+        {1,  "one"},
+        {2,  "two"},
+        {3,  "three"},
+        {4,  "four"},
+        {5,  "five"},
+        {6,  "six"},
+        {7,  "seven"},
+        {8,  "eight"},
+        {9,  "nine"},
         {10, "ten"},
         {11, "eleven"},
         {12, "twelve"},
         {13, "thirteen"},
         {20, "twenty"},
         {30, "thirty"},
+        {40, "forty"},
         {50, "fifty"},
         {80, "eighty"}
     };
+
+struct order_t
+{
+    number_t divisor;
+    number_t max;
+    string   separator;
+    string   suffix;
+};
+
+const order_t orders[] = {
+    {10,         100,           "-", "ty"},
+    {100,        1000,          " ", " hundred"},
+    {1000,       1000000,       " ", " thousand"},
+    {1000000,    1000000000,    " ", " million"},
+    {1000000000, 1000000000000, " ", " billion"}
+};
+
 }
 
 
 string in_english(number_t number)
 {
+    if (number_map.count(number))
+        return number_map.at(number);
+
     if (number > 13 && number < 20)
-        return numbers_map.at(number - 10) + "teen";
+        return number_map.at(number - 10) + "teen";
 
-    if (number >= 20 && number < 100 && (number % 10 == 0)) {
+    for (auto o : orders) {
 
-        if (numbers_map.count(number))
-            return numbers_map.at(number);
+        if (number >= o.divisor && number < o.max) {
 
-        return numbers_map.at(number / 10) + "ty";
+            if (number % o.divisor == 0)
+                return in_english(number / o.divisor) + o.suffix;
+
+            number_t reminder = number % o.divisor;
+            number_t div_part = number - reminder;
+
+            return in_english(div_part) + o.separator + in_english(reminder);
+        }
     }
 
-    if (number > 20 && number < 100) {
-
-        number_t ones = number % 10;
-        number_t tens = number - ones;
-
-        return in_english(tens) + '-' + in_english(ones);
-    }
-
-    if (number >= 100 && number < 1000) {
-
-        if (number % 100 == 0)
-            return in_english(number / 100) + " hundred";
-
-        number_t rest     = number % 100;
-        number_t hundreds = number - rest;
-
-        return in_english(hundreds) + ' ' + in_english(rest);
-    }
-
-    if (number >= 1000 && number < 1000000) {
-
-        cout << number << endl;
-
-        if (number % 1000 == 0)
-            return in_english(number / 1000) + " thousand";
-
-        number_t rest      = number % 1000;
-        number_t thousands = number - rest;
-
-        return in_english(thousands) + ' ' + in_english(rest);
-    }
-
-    return numbers_map.at(number);
+    throw domain_error("can't say the number");
 }
 
 
diff --git a/cpp/say/say.h b/cpp/say/say.h
index 99f9987..3251407 100644
--- a/cpp/say/say.h
+++ b/cpp/say/say.h
@@ -6,7 +6,7 @@
 
 namespace say {
 
-typedef unsigned long long number_t;
+typedef long long number_t;
 
 std::string in_english(number_t number);