Find anagram in JavaScript, running under node

Author: suresh-srinivas

puzzles/findAnagram/JavaScript/README.md

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+# Find An Anagram
+
+```
+node index.js apple
+Finding anagrams for apple
+[ 'a',
+  'ale',
+  'ape',
+  'apple',
+  'la',
+  'lap',
+  'lea',
+  'leap',
+  'pa',
+  'pal',
+  'pale',
+  'pap',
+  'pea',
+  'peal',
+  'pep',
+  'plea',
+  '' ]
+apple has 17 subanagrams. a, ale, ape, apple, la, lap, lea, leap, pa, pal, pale, pap, pea, peal, pep, plea, 
+```

puzzles/findAnagram/JavaScript/anagrams.js

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+// Code modified to work locally from https://github.com/evanchiu/alexa-anagram
+const fs = require('fs');
+const path = require('path');
+
+exports.getAnagrams = function(target, callback) {
+  getDictionary(function(err, dictionary) {
+    if (err) {
+      callback(err);
+    } else {
+      targetCountHash = getLetterCountHash(target);
+      subanagrams = [];
+      for (let i = 0; i < dictionary.length; i++) {
+        if (isSubanagram(targetCountHash, getLetterCountHash(dictionary[i]))) {
+          subanagrams.push(dictionary[i]);
+        }
+      }
+      callback(null, subanagrams);
+    }
+  });
+};
+
+function getDictionary(callback) {
+  let dictionaryFile = path.join(__dirname, 'data', '6of12.txt');
+//  console.log(dictionaryFile);
+  fs.readFile(dictionaryFile, function(err, data) {
+    if (err) {
+      callback(err);
+    } else {
+      callback(null, data.toString().split('\n'));
+    }
+  });
+}
+
+function isSubanagram(base, candidate) {
+  for (let letter in candidate) {
+    if (!base[letter] || base[letter] < candidate[letter]) {
+      return false;
+    }
+  }
+  return true;
+}
+
+function getLetterCountHash(word) {
+  let letters = word.split('');
+  let countHash = {};
+  for (let i = 0; i < letters.length; i++) {
+    if (countHash[letters[i]]) {
+      countHash[letters[i]] += 1;
+    } else {
+      countHash[letters[i]] = 1;
+    }
+  }
+  return countHash;
+}
+