Implement recite function with constexpr arrays and proper newline formatting

Author: alienx5499

exercises/practice/twelve-days/.meta/example.cpp

@@ -1,51 +1,73 @@
-#include "twelve_days.h"
 #include <array>
 #include <string>
 
+#include "twelve_days.h"
+
 namespace twelve_days {
 
-std::string verse(int day) {
-    const std::array<std::string, 13> ordinals = {
-        "", "first", "second", "third", "fourth", "fifth", "sixth",
-        "seventh", "eighth", "ninth", "tenth", "eleventh", "twelfth"
-    };
-    
-    const std::array<std::string, 13> gifts = {
-        "", "a Partridge in a Pear Tree", "two Turtle Doves", "three French Hens",
-        "four Calling Birds", "five Gold Rings", "six Geese-a-Laying",
-        "seven Swans-a-Swimming", "eight Maids-a-Milking", "nine Ladies Dancing",
-        "ten Lords-a-Leaping", "eleven Pipers Piping", "twelve Drummers Drumming"
-    };
-    
-    auto result = std::string{"On the "} + ordinals[day] + " day of Christmas my true love gave to me: ";
-    
-    for (int i = day; i >= 1; --i) {
-        if (i == day) {
-            result += gifts[i];
-        } else if (i == 1) {
-            result += std::string{", and "} + gifts[i];
-        } else {
-            result += std::string{", "} + gifts[i];
+std::string recite(int start_day, int end_day) {
+    constexpr std::array<const char*, 13> ordinals = {
+        "",        "first",  "second", "third", "fourth",   "fifth",  "sixth",
+        "seventh", "eighth", "ninth",  "tenth", "eleventh", "twelfth"};
+
+    constexpr std::array<const char*, 13> gifts = {"",
+                                                   "a Partridge in a Pear Tree",
+                                                   "two Turtle Doves",
+                                                   "three French Hens",
+                                                   "four Calling Birds",
+                                                   "five Gold Rings",
+                                                   "six Geese-a-Laying",
+                                                   "seven Swans-a-Swimming",
+                                                   "eight Maids-a-Milking",
+                                                   "nine Ladies Dancing",
+                                                   "ten Lords-a-Leaping",
+                                                   "eleven Pipers Piping",
+                                                   "twelve Drummers Drumming"};
+
+    if (start_day == end_day) {
+        // Single verse case
+        auto result = std::string{"On the "} +
+                      std::string{ordinals[start_day]} +
+                      " day of Christmas my true love gave to me: ";
+
+        for (int i = start_day; i >= 1; --i) {
+            if (i == start_day) {
+                result += std::string{gifts[i]};
+            } else if (i == 1) {
+                result += std::string{", and "} + std::string{gifts[i]};
+            } else {
+                result += std::string{", "} + std::string{gifts[i]};
+            }
         }
-    }
-    
-    result += ".";
-    return result;
-}
 
-std::string lyrics(int start_day, int end_day) {
-    std::string result = "";
-    for (int i = start_day; i <= end_day; ++i) {
-        if (i > start_day) {
-            result += "\n\n";
+        result += ".\n";
+        return result;
+    } else {
+        // Multiple verses case
+        std::string result = "";
+        for (int i = start_day; i <= end_day; ++i) {
+            if (i > start_day) {
+                result += "\n";
+            }
+
+            auto verse = std::string{"On the "} + std::string{ordinals[i]} +
+                         " day of Christmas my true love gave to me: ";
+
+            for (int j = i; j >= 1; --j) {
+                if (j == i) {
+                    verse += std::string{gifts[j]};
+                } else if (j == 1) {
+                    verse += std::string{", and "} + std::string{gifts[j]};
+                } else {
+                    verse += std::string{", "} + std::string{gifts[j]};
+                }
+            }
+
+            verse += ".\n";
+            result += verse;
         }
-        result += verse(i);
+        return result;
     }
-    return result;
-}
-
-std::string lyrics(int end_day) {
-    return lyrics(1, end_day);
 }
 
 }  // namespace twelve_days

exercises/practice/twelve-days/.meta/example.h

@@ -4,8 +4,6 @@
 
 namespace twelve_days {
 
-std::string verse(int day);
-std::string lyrics(int start_day, int end_day);
-std::string lyrics(int end_day);
+std::string recite(int start_day, int end_day);
 
 }  // namespace twelve_days

exercises/practice/twelve-days/twelve_days.cpp

@@ -1,7 +1,3 @@
 #include "twelve_days.h"
-#include <vector>
-#include <string>
 
-namespace twelve_days {
-
-}  // namespace twelve_days
+namespace twelve_days {}  // namespace twelve_days

exercises/practice/twelve-days/twelve_days.h

@@ -1,7 +1,3 @@
 #pragma once
 
-#include <string>
-
-namespace twelve_days {
-
-}  // namespace twelve_days
+namespace twelve_days {}  // namespace twelve_days