Slow version of pattern hash function

a.c

@@ -17,6 +17,8 @@ string ToUpper(string s) {
   return s2;
 }
 
+// --------------------------------------------------------------------------------
+//-Word
 struct Word {
   Word() {}  // default empty constructor
   Word(string s) : word(s) {}  // standard way of initialization
@@ -25,9 +27,27 @@ struct Word {
 typedef vector<Word> Words;
 typedef unordered_map<string, Word> WordMap;  // hash-table from stl
 
+// --------------------------------------------------------------------------------
+//-Library
 class Library {
 public:
   Library() {}  // hash-tables are automatically initialized
+  void FindWord(const string& s) const { // references are prefered instead of copies 
+    int len = s.length();  // cache the length to avoid multiple calls
+    for (const Word& w : words_) {  // references are prefered instead of copies
+      string temp = w.word;
+      if (len == temp.length()) {
+        for (int i=0; i<len; i++) {
+          if (s[i] == '-') {
+            temp[i] = '-';
+          }
+        }
+        if (s == temp) {
+          cout << w.word << "\n";  // print the original word
+        }
+      }
+    }
+  }
   bool IsWord(string s) const {
     auto it = word_map_.find(s);  // use iterator
     if (it == word_map_.end()) {
@@ -60,7 +80,7 @@ public:
   void ReadFromFile(string filename) {
     ifstream f;
     f.open(filename);
-    while (!f.eof()) {
+    while (f.is_open() && !f.eof()) {  // check for the file!
       string line;
       getline(f, line);
       // cout << line << "\n";
@@ -104,7 +124,7 @@ struct Grid {
   void LoadFromFile(string filename) {
     ifstream f;
     f.open("test");
-    while (!f.eof()) {
+    while (f.is_open() && !f.eof()) {  // check for the file
       string line;
       getline(f, line);
       // cout << line << "\n";
@@ -133,14 +153,8 @@ struct Grid {
 int main() {
   Library lib;
   lib.ReadFromFile("top_12000.txt");
-  //lib.ComputeStats();
-  //lib.PrintStats();
-
-  cout << lib.IsWord("DOG") << "\n";
-  cout << lib.IsWord("CAT") << "\n";
-  cout << lib.IsWord("THANKS") << "\n";
-  cout << lib.IsWord("TFAFAS") << "\n";
-  lib.DebugBuckets();
+  
+  lib.FindWord("D--");
 
   //Grid grid("MY GRID");
   //grid.LoadFromFile("test");