Update ex9_49.cpp

ch09/ex9_49.cpp

@@ -10,6 +10,9 @@
 //          A letter has a descender if, as with p or g, part of the letter extends below the line.
 //          Write a program that reads a file containing words and reports the longest word
 //          that contains neither ascenders nor descenders.
+//  
+//  @Refactor  @Yue Wang Jun 2015
+//
 
 #include <string>
 #include <fstream>
@@ -21,16 +24,15 @@ int main()
 {
     ifstream ifs("../data/letter.txt");
     if (!ifs) return -1;
-    string longest_word;
-    for (string word; ifs >> word; )
-        if (word.find_first_not_of("aceimnorsuvwxz") == string::npos &&
-            word.size() > longest_word.size())
-            longest_word = word;
-
-    cout << longest_word << endl;
-
-    ifs.close();
 
+    string longest;
+    auto update_with = [&longest](string const& curr)
+    {
+        if (string::npos == curr.find_first_not_of("aceimnorsuvwxz"))
+            longest = longest.size() < curr.size() ? curr : longest;
+    };
+    for (string curr; ifs >> curr; update_with(curr));
+    cout << longest << endl;
 
     return 0;
 }