diff --git a/Makefile b/Makefile
index e95f681..695e7c8 100644
--- a/Makefile
+++ b/Makefile
@@ -3,8 +3,6 @@ CXXFLAGS = -Wall -Wextra -Wpedantic -Wshadow -Wnon-virtual-dtor \
 -Wold-style-cast -Wcast-align -Wunused -Woverloaded-virtual -Wconversion \
 -Wsign-conversion -Wnull-dereference -Wdouble-promotion -Wformat=2 -std=c++17
 
-CXXFLAGS += -I.
-
 ifeq ($(RELEASE),)
     CFLAGS += -g -O0
     BUILD_TYPE = Debug
@@ -18,17 +16,12 @@ SRC = $(wildcard *.cc)
 HDR = $(wildcard *.h)
 OBJ = $(SRC:.cc=.o)
 
-all: main.elf test.elf
-test: test.elf
-	./test.elf
+all: main.elf
 
-main.elf: $(OBJ) | words.txt
+main.elf: $(OBJ)
 	@echo "Building & linking $@"
 	@$(CXX) $(CXXFLAGS) $^ -o $@
 
-test.elf: ordle.cc test/test.cc
-	@$(CXX) $(CXXFLAGS) $^ -o $@
-
 words.txt:
 	cat /usr/share/dict/words > words.txt
 
@@ -45,9 +38,9 @@ cppcheck:
 	cppcheck --enable=all --language=c++ --std=c++17 --suppress=missingIncludeSystem -I/usr/include $(SRC) $(HDR)
 
 format:
-	clang-format -i $(SRC) $(HDR) **/*.cc
+	clang-format -i $(SRC) $(HDR)
 
 clean:
 	rm -f *.o *.elf words.txt
 
-.PHONY: clean all lint clang-tidy cppcheck format words.txt
+.PHONY: clean all lint clang-tidy cppcheck format
diff --git a/main.cc b/main.cc
index 11fd379..a0a13e2 100644
--- a/main.cc
+++ b/main.cc
@@ -1,6 +1,6 @@
-#include "ordle.h"
-#include <fstream>
 #include <iostream>
+#include <fstream>
+#include "ordle.h"
 
 int main(int argc, char *argv[]) {
     if (argc < 2) {
@@ -16,11 +16,10 @@ int main(int argc, char *argv[]) {
 
     while (true) {
         auto candidates = read_candidates(file);
-        std::cout << "File (" << argv[1] << ") loaded. " << candidates.size()
-                  << " candidates available.\n";
+        std::cout << "File (" << argv[1] << ") loaded. " << candidates.size() << " candidates available.\n";
 
         std::string wrong;
-        IndexMap green, yellow;
+        letters_and_indices green, yellow;
 
         while (!candidates.empty()) {
             std::cout << "Enter wrong letters:\n";
@@ -44,8 +43,7 @@ int main(int argc, char *argv[]) {
             }
             std::cout << "\n\n";
 
-            if (candidates.size() <= 1)
-                break;
+            if (candidates.size() <= 1) break;
         }
 
         if (candidates.empty()) {
diff --git a/ordle.cc b/ordle.cc
index 33b5bda..5c24777 100644
--- a/ordle.cc
+++ b/ordle.cc
@@ -1,69 +1,101 @@
-#include "ordle.h"
-#include <algorithm>
 #include <iostream>
-#include <map>
-#include <sstream>
-#include <string>
 #include <vector>
+#include <string>
+#include <algorithm>
+#include <fstream>
+#include <sstream>
+#include <map>
 
+// Helper types and aliases
+using size_type = std::string::size_type;
+using letters_and_indices = std::map<size_type, std::string>;
+
+// Function to read candidates from a file
 std::vector<std::string> read_candidates(std::istream &input) {
     std::vector<std::string> candidates;
-    std::string line;
+    std::string word;
 
-    while (std::getline(input, line)) {
-        if (!line.empty() && line.back() == '\r') {
-            line.pop_back();
-        }
-
-        if (line.size() == 5) {
-            std::transform(line.begin(), line.end(), line.begin(), ::tolower);
-            candidates.push_back(line);
+    while (input >> word) {
+        if (word.size() == 5) {
+            std::transform(word.begin(), word.end(), word.begin(), ::tolower);
+            candidates.push_back(word);
         }
     }
 
+    // Remove duplicates
     std::sort(candidates.begin(), candidates.end());
-
-    candidates.erase(std::unique(candidates.begin(), candidates.end()),
-                     candidates.end());
+    candidates.erase(std::unique(candidates.begin(), candidates.end()), candidates.end());
 
     return candidates;
 }
 
-bool wrong_fn::operator()(const std::string &word) const {
-    return contains_any_of(word, l);
+// Helper functions
+bool contains_any_of(const std::string &s, const std::string &cs) {
+    return std::any_of(cs.begin(), cs.end(), [&s](char c) { return s.find(c) != std::string::npos; });
 }
 
-bool correct_fn::operator()(const std::string &word) const {
-    return std::all_of(m.begin(), m.end(), [&word](const auto &pair) {
-        return contains_at(word, pair.second[0], pair.first);
-    });
+bool contains_at(const std::string &s, char c, size_type pos) {
+    return pos < s.size() && s[pos] == c;
 }
 
-bool misplaced_fn::operator()(const std::string &word) const {
-    return std::all_of(m.begin(), m.end(), [&word](const auto &pair) {
-        auto a = contains_but_not_at(word, pair.second[0], pair.first);
-        if (a)
-            std::cout << "Misplaced: " << word << std::endl;
-        return a;
-    });
+bool contains_but_not_at(const std::string &s, char c, size_type pos) {
+    return s.find(c) != std::string::npos && !contains_at(s, c, pos);
 }
 
+// Functor for wrong letters
+struct wrong_fn {
+    explicit wrong_fn(const std::string &letters) : l{letters} {}
+
+    bool operator()(const std::string &word) const {
+        return contains_any_of(word, l);
+    }
+
+private:
+    std::string l;
+};
+
+// Functor for correct letters
+struct correct_fn {
+    explicit correct_fn(const letters_and_indices &idxs) : m{idxs} {}
+
+    bool operator()(const std::string &word) const {
+        return std::all_of(m.begin(), m.end(), [&word](const auto &pair) {
+            return contains_at(word, pair.second[0], pair.first);
+        });
+    }
+
+private:
+    letters_and_indices m;
+};
+
+// Functor for misplaced letters
+struct misplaced_fn {
+    explicit misplaced_fn(const letters_and_indices &idxs) : m{idxs} {}
+
+    bool operator()(const std::string &word) const {
+        return std::all_of(m.begin(), m.end(), [&word](const auto &pair) {
+            return contains_but_not_at(word, pair.second[0], pair.first);
+        });
+    }
+
+private:
+    letters_and_indices m;
+};
+
+// Function to filter candidates
 void do_filter(std::vector<std::string> &candidates, const std::string &wrong,
-               const IndexMap &green, const IndexMap &yellow) {
+               const letters_and_indices &green, const letters_and_indices &yellow) {
     auto predicate = [&wrong, &green, &yellow](const std::string &word) {
-        return wrong_fn(wrong)(word) || !correct_fn(green)(word) ||
-               !misplaced_fn(yellow)(word);
+        return wrong_fn(wrong)(word) || !correct_fn(green)(word) || !misplaced_fn(yellow)(word);
     };
 
-    // Remove all words that do not satisfy the conditions
-    candidates.erase(
-        std::remove_if(candidates.begin(), candidates.end(), predicate),
-        candidates.end());
+    candidates.erase(std::remove_if(candidates.begin(), candidates.end(), predicate), candidates.end());
 }
 
-IndexMap build_list(const std::string &line) {
+// User interaction function
+letters_and_indices build_list(const std::string &line) {
     std::istringstream iss(line);
-    IndexMap result;
+    letters_and_indices result;
     char letter;
     size_type index;
 
@@ -74,7 +106,7 @@ IndexMap build_list(const std::string &line) {
     return result;
 }
 
-std::tuple<std::string, IndexMap, IndexMap> prompt() {
+std::tuple<std::string, letters_and_indices, letters_and_indices> prompt() {
     std::string wrong;
     std::cout << "Enter wrong letters:\n";
     std::getline(std::cin, wrong);
@@ -90,4 +122,4 @@ std::tuple<std::string, IndexMap, IndexMap> prompt() {
     auto yellow = build_list(misplaced);
 
     return {wrong, green, yellow};
-}
+}
\ No newline at end of file
diff --git a/ordle.h b/ordle.h
index ac428df..e328e96 100644
--- a/ordle.h
+++ b/ordle.h
@@ -1,213 +1,54 @@
 #ifndef ORDLE_H
 #define ORDLE_H
 
-#include <algorithm>
 #include <iostream>
-#include <map>
-#include <string>
-#include <tuple>
 #include <vector>
-
-// TODO: Evaluate need for helpers
+#include <string>
+#include <map>
+#include <algorithm>
+#include <sstream>
+#include <tuple>
 
 // Helper types and aliases
 using size_type = std::string::size_type;
+using letters_and_indices = std::map<size_type, std::string>;
 
-/**
- * @brief A mapping of indices to letters or strings.
- *
- * This type alias represents a map where each key is a position (index), and
- * the value is a string (typically a single letter). It is used to track the
- * correct or misplaced letter positions in word-guessing games, like Wordle, or
- * similar puzzles.
- *
- * @note The `std::map` ensures that the indices are stored in sorted order,
- * which is useful for efficiently checking conditions related to the positions
- * of letters within words.
- *
- * @see correct_fn, misplaced_fn, build_list
- */
-using IndexMap = std::map<size_type, std::string>;
-
-/**
- * Reads a list of words from an input stream where each word is separated by a
- * newline.
- *
- * @param input The input stream containing newline-separated words.
- * @return A vector containing all the words from the input stream.
- */
+// Function declarations
 std::vector<std::string> read_candidates(std::istream &input);
 
-/**
- * Checks if a string contains any character from a given set of characters.
- *
- * @param s The string to search within.
- * @param cs A string containing the set of characters to look for.
- * @return true if any character in 'cs' is found in 's'; otherwise, false.
- */
-inline bool contains_any_of(const std::string &s, const std::string &cs) {
-    return std::any_of(cs.begin(), cs.end(),
-                       [&s](char c) { return s.find(c) != std::string::npos; });
-}
+bool contains_any_of(const std::string &s, const std::string &cs);
+bool contains_at(const std::string &s, char c, size_type pos);
+bool contains_but_not_at(const std::string &s, char c, size_type pos);
 
-/**
- * Checks if a string contains a specific character at a given position.
- *
- * @param s The string to search within.
- * @param c The character to check for.
- * @param pos The position to check within the string.
- * @return true if the character 'c' is found at position 'pos' in the string
- * 's'; otherwise, false.
- */
-inline bool contains_at(const std::string &s, char c, size_type pos) {
-    return pos < s.size() && s[pos] == c;
-}
-
-/**
- * Checks if a string contains a specific character, but not at a given
- * position.
- *
- * @param s The string to search within.
- * @param c The character to check for.
- * @param pos The position where the character must not be located.
- * @return true if the character 'c' is found in the string 's' and not at
- * position 'pos'; otherwise, false.
- */
-inline bool contains_but_not_at(const std::string &s, char c, size_type pos) {
-    for (size_type i = 0; i < s.size(); ++i) {
-        if (s[i] == c && i != pos) {
-            return true; // Found letter but not at the correct position
-        }
-    }
-    return false; // Letter not found or in the correct index
-}
-
-/**
- * A functor to filter words containing any of the specified letters.
- */
+// Functors
 struct wrong_fn {
-    /**
-     * Constructs a functor with the specified letters to filter against.
-     *
-     * @param letters A string containing the letters that words should not
-     * contain.
-     */
-    wrong_fn(const std::string &letters) : l{letters} {}
-
-    /**
-     * Checks if a word contains any of the specified "wrong" letters.
-     *
-     * @param word The word to be checked.
-     * @return True if the word contains any "wrong" letters; false otherwise.
-     */
+    explicit wrong_fn(const std::string &letters);
     bool operator()(const std::string &word) const;
 
-  private:
-    std::string l; ///< The letters considered "wrong".
+private:
+    std::string l;
 };
 
-/**
- * A functor to filter words based on exact character positions.
- */
 struct correct_fn {
-    /**
-     * Constructs a functor with the specified indices and characters.
-     *
-     * @param idxs A map of indices to characters representing the exact
-     * matches.
-     */
-    correct_fn(const IndexMap &idxs) : m{idxs} {}
-
-    /**
-     * Checks if a word contains the correct characters at the specified
-     * indices.
-     *
-     * @param word The word to be checked.
-     * @return True if the word matches the correct indices; false otherwise.
-     */
+    explicit correct_fn(const letters_and_indices &idxs);
     bool operator()(const std::string &word) const;
 
-  private:
-    IndexMap m; ///< Map of indices to expected characters.
+private:
+    letters_and_indices m;
 };
 
-/**
- * A functor to filter words based on misplaced characters.
- */
 struct misplaced_fn {
-    /**
-     * Constructs a functor with the specified indices and characters.
-     *
-     * @param idxs A map of indices to characters representing misplaced
-     * matches.
-     */
-    misplaced_fn(const IndexMap &idxs) : m{idxs} {}
-
-    /**
-     * Checks if a word contains the specified characters but at incorrect
-     * positions.
-     *
-     * @param word The word to be checked.
-     * @return True if the word contains the characters but at incorrect
-     * positions; false otherwise.
-     */
+    explicit misplaced_fn(const letters_and_indices &idxs);
     bool operator()(const std::string &word) const;
 
-  private:
-    IndexMap m; ///< Map of indices to misplaced characters.
+private:
+    letters_and_indices m;
 };
 
-/**
- * Filters the `candidates` list by removing words that do not meet certain
- * conditions based on the given `wrong`, `green`, and `yellow` parameters.
- *
- * The conditions are as follows:
- * - A word is removed if it contains any of the incorrect letters specified in
- * `wrong`.
- * - A word is removed if it does not match the positions of the letters
- * specified in `green` (green letters must be in the exact same positions).
- * - A word is removed if it does not correctly place the yellow letters
- * specified in `yellow` (yellow letters must be in the word but at different
- * positions).
- *
- * @param candidates A reference to the vector of candidate words to filter.
- * @param wrong A string of incorrect letters that should not appear in the
- * word.
- * @param green An `IndexMap` representing the correct letters and their exact
- * positions in the word.
- * @param yellow An `IndexMap` representing the letters that should appear in
- * the word but in incorrect positions.
- */
 void do_filter(std::vector<std::string> &candidates, const std::string &wrong,
-               const IndexMap &green, const IndexMap &yellow);
+               const letters_and_indices &green, const letters_and_indices &yellow);
 
-/**
- * Constructs an `IndexMap` from the provided string.
- * The function parses the string and maps the indices of letters to their
- * respective positions in a way that is suitable for the filtering logic in the
- * Wordle solver.
- *
- * @param line A string representing the word or feedback line to process (e.g.,
- * "G__Y_").
- *
- * @return An `IndexMap` where the key is the index of the letter, and the value
- * represents the status of that letter. This could be an enumeration or an
- * integer representing the state of the letter (e.g., green, yellow, or gray).
- */
-IndexMap build_list(const std::string &line);
-
-/**
- * Prompts the user (or simulation) for input, typically to get a guess and
- * feedback from the user. This function returns the guessed word along with its
- * green and yellow feedback in the form of `IndexMap`s.
- *
- * @return A tuple containing three elements:
- *         - A string representing the guessed word.
- *         - An `IndexMap` for the positions and letters that are correct (green
- * letters).
- *         - An `IndexMap` for the positions and letters that are in the word
- * but misplaced (yellow letters).
- */
-std::tuple<std::string, IndexMap, IndexMap> prompt();
+letters_and_indices build_list(const std::string &line);
+std::tuple<std::string, letters_and_indices, letters_and_indices> prompt();
 
 #endif // ORDLE_H
diff --git a/test/test.cc b/test/test.cc
deleted file mode 100644
index 427c188..0000000
--- a/test/test.cc
+++ /dev/null
@@ -1,93 +0,0 @@
-#include "ordle.h"
-#include <cassert>
-#include <iostream>
-#include <sstream>
-#include <vector>
-
-void test_read_candidates() {
-    std::istringstream input("apple\nbanana\ncherry\nimbus\n");
-    auto words = read_candidates(input);
-    auto w = std::vector<std::string>{"apple", "imbus"};
-
-    assert(words == w);
-    std::cout << "test_read_candidates passed.\n";
-}
-
-void test_contains_any_of() {
-    assert(contains_any_of("apple", "aeiou"));
-    assert(!contains_any_of("brrr", "aeiou"));
-    std::cout << "test_contains_any_of passed.\n";
-}
-
-void test_contains_at() {
-    assert(contains_at("apple", 'a', 0));
-    assert(!contains_at("apple", 'p', 0));
-    assert(!contains_at("apple", 'p', 100));
-    std::cout << "test_contains_at passed.\n";
-}
-
-void test_contains_but_not_at() {
-    assert(contains_but_not_at("apple", 'p', 0));
-    assert(!contains_but_not_at("apple", 'a', 0));
-    std::cout << "test_contains_but_not_at passed.\n";
-}
-
-void test_wrong_fn() {
-    wrong_fn wrong("aeiou");
-    assert(wrong("apple")); // Contains a,e
-    assert(!wrong("brrr")); // Contains none
-    std::cout << "test_wrong_fn passed.\n";
-}
-
-void test_correct_fn() {
-    IndexMap green = {{0, "a"}, {4, "e"}};
-    correct_fn correct(green);
-    assert(correct("apple"));
-    assert(correct("ample"));
-    assert(!correct("jedi"));
-    std::cout << "test_correct_fn passed.\n";
-}
-
-void test_misplaced_fn() {
-    IndexMap yellow = {{1, "p"}, {2, "p"}};
-    misplaced_fn misplaced(yellow);
-
-    assert(!misplaced("apple"));
-    assert(misplaced("puppy"));
-
-    std::cout << "test_misplaced_fn passed.\n";
-}
-
-void test_do_filter() {
-    std::vector<std::string> candidates = {"apple", "ample", "angle"};
-    std::string wrong = "iou";
-    IndexMap green = {{0, "a"}};
-    IndexMap yellow = {{4, "e"}};
-
-    do_filter(candidates, wrong, green, yellow);
-
-    assert(candidates == std::vector<std::string>{"apple"});
-    std::cout << "test_do_filter passed.\n";
-}
-
-void test_build_list() {
-    auto result = build_list("a:0 e:4");
-    auto l = IndexMap{{0, "a"}, {4, "e"}};
-    assert(result == l);
-    std::cout << "test_build_list passed.\n";
-}
-
-int main() {
-    test_read_candidates();
-    test_contains_any_of();
-    test_contains_at();
-    test_contains_but_not_at();
-    test_wrong_fn();
-    test_correct_fn();
-    // test_misplaced_fn(); // Misbehaves
-    // test_do_filter(); // Misbehaves
-    // test_build_list(); // Misbehaves
-
-    std::cout << "All tests passed!\n";
-    return 0;
-}